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2. ASASSN-18aan: An Eclipsing SU UMa-type Cataclysmic Variable with a 3.6-hour Orbital Period and a Late G-type Secondary Star

Author

Wakamatsu, Yasuyuki, Thorstensen, John R., Kojiguchi, Naoto, Isogai, Keisuke, Kimura, Mariko, Ohnishi, Ryuhei, Kato, Taichi, Itoh, Hiroshi, Sugiura, Yuki, Sumiya, Sho, Matsumoto, Hanami, Ito, Daiki, Nikai, Kengo, Akitaya, Hiroshi, Ishioka, Chihiro, Oide, Kohei, Kanai, Takahiro, Uzawa, Yoshinori, Oasa, Yumiko, Tordai, Tamás, Vanmunster, Tonny, Shugarov, Sergey Yu., Yamanaka, Masayuki, Sasada, Mahito, Takagi, Kengo, Nishinaka, Yuki, Yamazaki, Yuina, Otsubo, Ikki, Nakaoka, Tatsuya, Murata, Katsuhiro L., Ohsawa, Ryou, Morita, Masahiro, Ichiki, Makoto, Dufoer, Sjoerd, Mizutani, Masanori, Horiuchi, Takashi, Tozuka, Miyako, Takayama, Masaki, Ohshima, Tomohito, Saito, Tomoki, Dubovsky, Pavol A., Stone, Geoff, Miller, Ian, and Nogami, Daisaku

Subjects
Astrophysics - Solar and Stellar Astrophysics
Abstract

We report photometric and spectroscopic observations of the eclipsing SU UMa-type dwarf nova ASASSN-18aan. We observed the 2018 superoutburst with 2.3 mag brightening and found the orbital period ($P_{\rm orb}$) to be 0.149454(3) d, or 3.59 hr. This is longward of the period gap, establishing ASASSN-18aan as one of a small number of long-$P_{\rm orb}$ SU UMa-type dwarf novae. The estimated mass ratio, ($q=M_2/M_1 = 0.278(1)$), is almost identical to the upper limit of tidal instability by the 3:1 resonance. From eclipses, we found that the accretion disk at the onset of the superoutburst may reach the 3:1 resonance radius, suggesting that the superoutburst of ASASSN-18aan results from the tidal instability. Considering the case of long-$P_{\rm orb}$ WZ Sge-type dwarf novae, we suggest that the tidal dissipation at the tidal truncation radius is enough to induce SU UMa-like behavior in relatively high-$q$ systems such as SU UMa-type dwarf novae, but that this is no longer effective in low-$q$ systems such as WZ Sge-type dwarf novae. The unusual nature of the system extends to the secondary star, for which we find a spectral type of G9, much earlier than typical for the orbital period, and a secondary mass $M_2$ of around 0.18 M$_{\odot}$, smaller than expected for the orbital period and the secondary's spectral type. We also see indications of enhanced sodium abundance in the secondary's spectrum. Anomalously hot secondaries are seen in a modest number of other CVs and related objects. These systems evidently underwent significant nuclear evolution before the onset of mass transfer. In the case of ASASSN-18aan, this apparently resulted in a mass ratio lower than typically found at the system's $P_{\rm orb}$, which may account for the occurrence of a superoutburst at this relatively long period., Comment: 17 pages, 14 figures, accepted for publication in PASJ

Published
2021
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3. Survey of Period Variations of Superhumps in SU UMa-Type Dwarf Novae. X: The Tenth Year (2017)

Author

Kato, Taichi, Isogai, Keisuke, Wakamatsu, Yasuyuki, Hambsch, Franz-Josef, Itoh, Hiroshi, Tordai, Tamas, Vanmunster, Tonny, Dubovsky, Pavol A., Kudzej, Igor, Medulka, Tomas, Kimura, Mariko, Ohnishi, Ryuhei, Monard, Berto, Pavlenko, Elena P., Antonyuk, Kirill A., Pit, Nikolaj V., Antonyuk, Oksana I., Babina, Julia V., Baklanov, Aleksei V., Sosnovskij, Aleksei A., Pickard, Roger D., Miller, Ian, Maeda, Yutaka, de Miguel, Enrique, Brincat, Stephen M., Licchelli, Domenico, Cook, Lewis M., Shugarov, Sergey Yu., Zaostrojnykh, Anna M., Chochol, Drahomir, Golysheva, Polina, Katysheva, Natalia, Zubareva, Alexandra M., Stone, Geoff, Kasai, Kiyoshi, Starr, Peter, Littlefield, Colin, Kiyota, Seiichiro, Andreev, Maksim V., Sergeev, Alexandr V., Ruiz, Javier, Myers, Gordon, Simon, Andrii O., Vasylenko, Volodymyr V., Soldan, Francisco, Ogmen, Yenal, Nakajima, Kazuhiro, Nelson, Peter, Masi, Gianluca, Menzies, Kenneth, Sabo, Richard, Bolt, Greg, Dvorak, Shawn, Stanek, Krzysztof Z., Shields, Joseph V., Kochanek, Christopher S., Holoien, Thomas W. -S., Shappee, Benjamin, Prieto, Jose L., Kojima, Tadashi, Nishimura, Hideo, Kaneko, Shizuo, Fujikawa, Shigehisa, Stubbings, Rod, Muyllaert, Eddy, Poyner, Gary, Moriyama, Masayuki, Maehara, Hiroyuki, Schmeer, Patrick, and Denisenko, Denis

Subjects
Astrophysics - Solar and Stellar Astrophysics
Abstract

Continuing the project described by Kato et al. (2009, PASJ, 61, S395, arXiv/0905.1757), we collected times of superhump maxima for 102 SU UMa-type dwarf novae observed mainly during the 2017 season and characterized these objects. WZ Sge-type stars identified in this study are PT And, ASASSN-17ei, ASASSN-17el, ASASSN-17es, ASASSN-17fn, ASASSN-17fz, ASASSN-17hw, ASASSN-17kd, ASASSN-17la, PNV J20205397+2508145 and TCP J00332502-3518565. We obtained new mass ratios for 7 objects using growing superhumps (stage A). ASASSN-17gf is an EI Psc-type object below the period minimum. CRTS J080941.3+171528 and DDE 51 are objects in the period gap and both showed long-lasting phase of stage A superhumps. We also summarized the recent advances in understanding of SU UMa-type and WZ Sge-type dwarf novae., Comment: The main text and Supporting information are combined in this arXiv version. Accepted for publication in PASJ, author list has been corrected. Follow-up to arXiv:1706.03870, arXiv:1605.06221, ... , arXiv:1009.5444, arXiv:0912.4321

Published
2019
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4. On the Nature of Long-Period Dwarf Novae with Rare and Low-Amplitude Outbursts

Author

Kimura, Mariko, Kato, Taichi, Maehara, Hiroyuki, Ishioka, Ryoko, Monard, Berto, Nakajima, Kazuhiro, Stone, Geoff, Pavlenko, Elena P., Antonyuk, Oksana I., Pit, Nikolai V., Sosnovskij, Aleksei A., Katysheva, Natalia, Richmond, Michael, Michel, Raúl, Matsumoto, Katsura, Kojiguchi, Naoto, Sugiura, Yuki, Tei, Shihei, Yamaura, Kenta, Cook, Lewis M., Sabo, Richard, Miller, Ian, Goff, William, Kiyota, Seiichiro, Shugarov, Sergey Yu., Golysheva, Polina, Vozyakova, Olga, Brincat, Stephen M., Itoh, Hiroshi, Tordai, Tamás, Littlefield, Colin, Pickard, Roger D., Tanabe, Kenji, Kinugawa, Kenzo, Honda, Satoshi, Taguchi, Hikaru, Hashimoto, Osamu, and Nogami, Daisaku

Subjects
Astrophysics - Solar and Stellar Astrophysics
Abstract

There are several peculiar long-period dwarf-nova like objects, which show rare, low-amplitude outbursts with highly ionized emission lines. 1SWASP J162117$+$441254, BD Pav, and V364 Lib belong to this kind of objects. Some researchers even doubt whether 1SWASP J1621 and V364 Lib have the same nature as normal dwarf novae. We studied the peculiar outbursts in these three objects via our optical photometry and spectroscopy, and performed numerical modeling of their orbital variations to investigate their properties. We found that their outbursts lasted for a long interval (a few tens of days), and that slow rises in brightness were commonly observed during the early stage of their outbursts. Our analyses and numerical modeling suggest that 1SWASP J1621 has a very high inclination, close to 90 deg, plus a faint hot spot. Although BD Pav seems to have a slightly lower inclination ($\sim$75 deg), the other properties are similar to those in 1SWASP J1621. On the other hand, V364 Lib appears to have a massive white dwarf, a hot companion star, and a low inclination ($\sim$35 deg). In addition, these three objects possibly have low transfer rate and/or large disks originating from the long orbital periods. We find that these properties of the three objects can explain their infrequent and low-amplitude outbursts within the context of the disk instability model in normal dwarf novae without strong magnetic field. In addition, we suggest that the highly-ionized emission lines in outburst are observed due to a high inclination and/or a massive white dwarf. More instances of this class of object may be unrecognized, since their unremarkable outbursts can be easily overlooked., Comment: 17 pages, 18 figures, 2 tables with supporting information. Accepted for publication in PASJ

Published
2018
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5. ASASSN-16dt and ASASSN-16hg: Promising Candidates for a Period Bouncer

Author

Kimura, Mariko, Isogai, Keisuke, Kato, Taichi, Taguchi, Kenta, Wakamatsu, Yasuyuki, Hambsch, Franz-Josef, Monard, Berto, Myers, Gordon, Dvorak, Shawn, Starr, Peter, Brincat, Stephen M., de Miguel, Enrique, Ulowetz, Joseph, Itoh, Hiroshi, Stone, Geoff, and Nogami, Daisaku

Subjects
Astrophysics - Solar and Stellar Astrophysics
Abstract

We present optical photometry of superoutbursts in 2016 of two WZ Sge-type dwarf novae (DNe), ASASSN-16dt and ASASSN-16hg. Their light curves showed a dip in brightness between the first plateau stage with no ordinary superhumps (or early superhumps) and the second plateau stage with ordinary superhumps. We find that the dip is produced by slow evolution of the 3:1 resonance tidal instability and that it would be likely observed in low mass-ratio objects. The estimated mass ratio ($q \equiv M_{2}/M_{1}$) from the period of developing (stage A) superhumps (0.06420(3) d) was 0.036(2) in ASASSN-16dt. Additionally, its superoutburst has many properties similar to those in other low-$q$ WZ Sge-type DNe: long-lasting stage A superhumps, small superhump amplitudes, long delay of ordinary superhump appearance, and slow decline rate in the plateau stage with superhumps. The very small mass ratio and observational characteristics suggest that this system is one of the best candidates for a period bouncer -- a binary accounting for the missing population of post-period minimum cataclysmic variables. Although it is not clearly verified due to the lack of detection of stage A superhumps, ASASSN-16hg might be a possible candidate for a period bouncer on the basis of the morphology of its light curves and the small superhump amplitudes. Many outburst properties of period-bouncer candidates would originate from the small tidal effects by their secondary stars., Comment: 11 pages, 11 figures, 2 tables, accepted for publication in PASJ, including 5 supplementary tables

Published
2018
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6. The First Post-Kepler Brightness Dips of KIC 8462852

Author

Boyajian, Tabetha S., Alonso, Roi, Ammerman, Alex, Armstrong, David, Ramos, A. Asensio, Barkaoui, K., Beatty, Thomas G., Benkhaldoun, Z., Benni, Paul, Bentley, Rory, Berdyugin, Andrei, Berdyugina, Svetlana, Bergeron, Serge, Bieryla, Allyson, Blain, Michaela G., Blanco, Alicia Capetillo, Bodman, Eva H. L., Boucher, Anne, Bradley, Mark, Brincat, Stephen M., Brink, Thomas G., Briol, John, Brown, David J. A., Budaj, J., Burdanov, A., Cale, B., Carbo, Miguel Aznar, Garcia, R. Castillo, Clark, Wendy J, Clayton, Geoffrey C., Clem, James L., Coker, Phillip H, Cook, Evan M., Copperwheat, Chris M., Curtis, J., Cutri, R. M., Cseh, B., Cynamon, C. H., Daniels, Alex J., Davenport, James R. A., Deeg, Hans J., De Lorenzo, Roberto, De Jaeger, Thomas, Desrosiers, Jean-Bruno, Dolan, John, Dowhos, D. J., Dubois, Franky, Durkee, R., Dvorak, Shawn, Easley, Lynn, Edwards, N., Ellis, Tyler G., Erdelyi, Emery, Ertel, Steve, Farfán, Rafael. G., Farihi, J., Filippenko, Alexei V., Foxell, Emma, Gandolfi, Davide, Garcia, Faustino, Giddens, F., Gillon, M., González-Carballo, Juan-Luis, González-Fernández, C., Hernández, J. I. González, Graham, Keith A., Greene, Kenton A., Gregorio, J., Hallakoun, Na'ama, Hanyecz, Ottó, Harp, G. R., Henry, Gregory W., Herrero, E., Hildbold, Caleb F., Hinzel, D., Holgado, G., Ignácz, Bernadett, Ivanov, Valentin D., Jehin, E., Jermak, Helen E., Johnston, Steve, Kafka, S., Kalup, Csilla, Kardasis, Emmanuel, Kaspi, Shai, Kennedy, Grant M., Kiefer, F., Kielty, C. L., Kessler, Dennis, Kiiskinen, H., Killestein, T. L., King, Ronald A., Kollar, V., Korhonen, H., Kotnik, C., Könyves-Tóth, Réka, Kriskovics, Levente, Krumm, Nathan, Krushinsky, Vadim, Kundra, E., Lachapelle, Francois-Rene, Lacourse, D., Lake, P., Lam, Kristine, Lamb, Gavin P., Lane, Dave, Lau, Marie Wingyee, Lewin, Pablo, Lintott, Chris, Lisse, Carey, Logie, Ludwig, Longeard, Nicolas, Villanueva, M. Lopez, Ludington, E. Whit, Mainzer, A., Malo, Lison, Maloney, Chris, Mann, A., Mantero, A., Marengo, Massimo, Marchant, Jon, González, M. J. Martinez, Masiero, Joseph R., Mauerhan, Jon C., Mccormac, James, Mcneely, Aaron, Meng, Huan Y. A., Miller, Mike, Molnar, Lawrence A., Morales, J. C., Morris, Brett M., Muterspaugh, Matthew W., Nespral, David, Nugent, C. R., Nugent, Katherine M., Odasso, A., O'keeffe, Derek, Oksanen, A., O'meara, John M., Ordasi, András, Osborn, Hugh, Ott, John J., Parks, J. R., Perez, Diego Rodriguez, Petriew, Vance, Pickard, R., Pál, András, Plavchan, P., Plaza, C. Westendorp, Pollacco, Don, Nuñez, F. Pozo, Pozuelos, F. J., Rau, Steve, Redfield, Seth, Relles, Howard, Ribas, I., Richards, Jon, Saario, Joonas L. O., Safron, Emily J., Sallai, J. Martin, Sárneczky, Krisztián, Schaefer, Bradley E., Schumer, Clea F., Schwartzendruber, Madison, Siegel, Michael H., Siemion, Andrew P. V., Simmons, Brooke D., Simon, Joshua D., Simón-Diaz, S., Sitko, Michael L., Socas-Navarro, Hector, Sódor, Á., Starkey, Donn, Steele, Iain A., Stone, Geoff, Street, R. A., Sullivan, Tricia, Suomela, J., Swift, J. J., Szabó, Gyula M., Szabó, Róbert, Szakáts, Róbert, Szalai, Tamás, Tanner, Angelle M., Toledo-Padrón, B., Tordai, Tamás, Triaud, Amaury H. M. J., Turner, Jake D., Ulowetz, Joseph H., Urbanik, Marian, Vanaverbeke, Siegfried, Vanderburg, Andrew, Vida, Krisztián, Vietje, Brad P., Vinkó, József, Von Braun, K., Waagen, Elizabeth O., Walsh, Dan, Watson, Christopher A., Weir, R. C., Wenzel, Klaus, Williamson, Michael W., Wright, Jason T., Wyatt, M. C., Zheng, Weikang, and Zsidi, Gabriella

Subjects
Astrophysics - Solar and Stellar Astrophysics, Astrophysics - Earth and Planetary Astrophysics
Abstract

We present a photometric detection of the first brightness dips of the unique variable star KIC 8462852 since the end of the Kepler space mission in 2013 May. Our regular photometric surveillance started in October 2015, and a sequence of dipping began in 2017 May continuing on through the end of 2017, when the star was no longer visible from Earth. We distinguish four main 1-2.5% dips, named "Elsie," "Celeste," "Skara Brae," and "Angkor", which persist on timescales from several days to weeks. Our main results so far are: (i) there are no apparent changes of the stellar spectrum or polarization during the dips; (ii) the multiband photometry of the dips shows differential reddening favoring non-grey extinction. Therefore, our data are inconsistent with dip models that invoke optically thick material, but rather they are in-line with predictions for an occulter consisting primarily of ordinary dust, where much of the material must be optically thin with a size scale <<1um, and may also be consistent with models invoking variations intrinsic to the stellar photosphere. Notably, our data do not place constraints on the color of the longer-term "secular" dimming, which may be caused by independent processes, or probe different regimes of a single process., Comment: 19 pages, 8 figures, accepted for publication in ApJL

Published
2018
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7. ASASSN-16eg: New candidate of long-period WZ Sge-type dwarf nova

Author

Wakamatsu, Yasuyuki, Isogai, Keisuke, Kimura, Mariko, Kato, Taichi, Vanmunster, Tonny, Stone, Geoff, Tordai, Tamás, Richmond, Michael, Miller, Ian, Oksanen, Arto, Itoh, Hiroshi, Akazawa, Hidehiko, Kiyota, Seiichiro, de Miguel, Enrique, Pavlenko, Elena P., Antonyuk, Kirill A., Antonyuk, Oksana I., Neustroev, Vitaly V., Sjoberg, George, Dubovsky, Pavol A., Pickard, Roger D., and Nogami, Daisaku

Subjects
Astrophysics - Solar and Stellar Astrophysics
Abstract

We report on our photometric observations of the 2016 superoutburst of ASASSN-16eg. This object showed a WZ Sge-type superoutburst with prominent early superhumps with a period of 0.075478(8) d and a post-superoutburst rebrightening. During the superoutburst plateau, it showed ordinary superhumps with a period of 0.077880(3) d and a period derivative of 10.6(1.1) $\times$ 10$^{-5}$ in stage B. The orbital period ($P_{\rm orb}$), which is almost identical with the period of early superhumps, is exceptionally long for a WZ Sge-type dwarf nova. The mass ratio ($q$ = $M_2/M_1$) estimated from the period of developing (stage A) superhumps is 0.166(2), which is also very large for a WZ Sge-type dwarf nova. This suggests that the 2:1 resonance can be reached in such high-$q$ systems, contrary to our expectation. Such conditions are considered to be achieved if the mass-transfer rate is much lower than those in typical SU UMa-type dwarf novae that have comparable orbital periods to ASASSN-16eg and a resultant accumulation of a large amount of matter on the disk is realized at the onset of an outburst. We examined other candidates of long-period WZ Sge-type dwarf novae for their supercycles, which are considered to reflect the mass-transfer rate, and found that V1251 Cyg and RZ Leo have longer supercycles than those of other WZ Sge-type dwarf novae. This result indicates that these long-period objects including ASASSN-16eg have a low mass-transfer rate in comparison to other WZ Sge-type dwarf novae., Comment: 9 pages, 5 figures

Published
2017
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8. Survey of Period Variations of Superhumps in SU UMa-Type Dwarf Novae. IX: The Ninth Year (2016-2017)

Author

Kato, Taichi, Isogai, Keisuke, Hambsch, Franz-Josef, Vanmunster, Tonny, Itoh, Hiroshi, Monard, Berto, Tordai, Tamaas, Kimura, Mariko, Wakamatsu, Yasuyuki, Kiyota, Seiichiro, Miller, Ian, Starr, Peter, Kasai, Kiyoshi, Shugarov, Sergey Yu., Chochol, Drahomir, Katysheva, Natalia, Zaostrojnykh, Anna M., Sekeras, Matej, Kuznyetsova, Yuliana G., Kalinicheva, Eugenia S., Golysheva, Polina, Krushevska, Viktoriia, Maeda, Yutaka, Dubovsky, Pavol A., Kudzej, Igor, Pavlenko, Elena P., Antonyuk, Kirill A., Pit, Nikolaj V., Sosnovskij, Aleksei A., Antonyuk, Oksana I., Baklanov, Aleksei V., Pickard, Roger D., Kojiguchi, Naoto, Sugiura, Yuki, Tei, Shihei, Yamamura, Kenta, Matsumoto, Katsura, Ruiz, Javier, Stone, Geoff, Cook, Lewis M., de Miguel, Enrique, Akazawa, Hidehiko, Goff, William N., Morelle, Etienne, Kafka, Stella, Littlefield, Colin, Bolt, Greg, Dubois, Franky, Brincat, Stephen M., Maehara, Hiroyuki, Sakanoi, Takeshi, Kagitani, Masato, Imada, Akira, Voloshina, Irina B., Andreev, Maksim V., Sabo, Richard, Richmond, Michael, Rodda, Tony, Nelson, Peter, Nazarov, Sergey, Mishevskiy, Nikolay, Myers, Gordon, Denisenko, Denis, Stanek, Krzysztof Z., Shields, Joseph V., Kochanek, Christopher S., Holoien, Thomas W. -S., Shappee, Benjamin, Prieto, Jose L., Itagaki, Koh-ichi, Nishiyama, Koichi, Kabashima, Fujio, Stubbings, Rod, Schmeer, Patrick, Muyllaert, Eddy, Horie, Tsuneo, Shears, Jeremy, Poyner, Gary, and Moriyama, Masayuki

Subjects
Astrophysics - Solar and Stellar Astrophysics
Abstract

Continuing the project described by Kato et al. (2009, arXiv:0905.1757), we collected times of superhump maxima for 127 SU UMa-type dwarf novae observed mainly during the 2016--2017 season and characterized these objects. We provide updated statistics of relation between the orbital period and the variation of superhumps, the relation between period variations and the rebrightening type in WZ Sge-type objects. We obtained the period minimum of 0.05290(2)d and confirmed the presence of the period gap above the orbital period ~0.09d. We note that four objects (NY Her, 1RXS J161659.5+620014, CRTS J033349.8-282244 and SDSS J153015.04+094946.3) have supercycles shorter than 100d but show infrequent normal outbursts. We consider that these objects are similar to V503 Cyg, whose normal outbursts are likely suppressed by a disk tilt. These four objects are excellent candidates to search for negative superhumps. DDE 48 appears to be a member of ER UMa-type dwarf novae. We identified a new eclipsing SU UMa-type object MASTER OT J220559.40-341434.9. We observed 21 WZ Sge-type dwarf novae during this interval and reported 18 out of them in this paper. Among them, ASASSN-16js is a good candidate for a period bouncer. ASASSN-16ia showed a precursor outburst for the first time in a WZ Sge-type superoutburst. ASASSN-16kg, CRTS J000130.5+050624 and SDSS J113551.09+532246.2 are located in the period gap. We have newly obtained 15 orbital periods, including periods from early superhumps., Comment: 126 pages. 168 figures, accepted for publication in PASJ. For readers' convenience, combined version with Supplementary Information is provided. See Ancillary files for the PASJ version (correction in author list)

Published
2017
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9. OT J002656.6+284933 (CSS101212:002657+284933): An SU UMa-Type Dwarf Nova with Longest Superhump Period

Author

Kato, Taichi, Tordai, Tamas, Littlefield, Colin, Kasai, Kiyoshi, Shugarov, Sergey Yu., Katysheva, Natalia, Zaostrojnykh, Anna M., Pickard, Roger D., de Miguel, Enrique, Antonyuk, Kirill, Antonyuk, Oksana, Pavlenko, Elena P., Pit, Nikolai, Itoh, Hiroshi, Ruiz, Javier, Isogai, Keisuke, Kimura, Mariko, Wakamatsu, Yasuyuki, Vanmunster, Tonny, and Stone, Geoff

Subjects
Astrophysics - Solar and Stellar Astrophysics
Abstract

We observed the 2016 outburst of OT J002656.6+284933 (CSS101212:002657+284933) and found that it has the longest recorded [0.13225(1) d in average] superhumps among SU UMa-type dwarf novae. The object is the third known SU UMa-type dwarf nova above the period gap. The outburst, however, was unlike ordinary long-period SU UMa-type dwarf novae in that it showed two post-outburst rebrightenings. It showed superhump evolution similar to short-period SU UMa-type dwarf novae. We could constrain the mass ratio to less than 0.15 (most likely between 0.10 and 0.15) by using superhump periods in the early and post-superoutburst stages. These results suggest the possibility that OT J002656.6+284933 has an anomalously undermassive secondary and it should have passed a different evolutionary track from the standard one., Comment: 6 pages, 3 figures, accepted for publication in PASJ (Letters), Note added in proof has been added. Supplementary Information (si.pdf) is available in the source file

Published
2017
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10. RZ Leonis Minoris Bridging between ER Ursae Majoris-Type Dwarf Nova and Novalike System

Author

Kato, Taichi, Ishioka, Ryoko, Isogai, Keisuke, Kimura, Mariko, Imada, Akira, Miller, Ian, Masumoto, Kazunari, Nishino, Hirochika, Kojiguchi, Naoto, Kawabata, Miho, Sakai, Daisuke, Sugiura, Yuki, Furukawa, Hisami, Yamamura, Kenta, Kobayashi, Hiroshi, Matsumoto, Katsura, Wang, Shiang-Yu, Chou, Yi, Ngeow, Chow-Choong, Chen, Wen-Ping, Panwar, Neelam, Lin, Chi-Sheng, Hsiao, Hsiang-Yao, Guo, Jhen-Kuei, Lin, Chien-Cheng, Omarov, Chingis, Kusakin, Anatoly, Krugov, Maxim, Starkey, Donn R., Pavlenko, Elena P., Antonyuk, Kirill A., Sosnjvskij, Aleksei A., Antonyuk, Oksana I., Pit, Nikolai V., Baklanov, Alex V., Babina, Julia V., Itoh, Hiroshi, Padovan, Stefano, Akazawa, Hidehiko, Kafka, Stella, de Miguel, Enrique, Pickard, Roger D., Kiyota, Seiichiro, Shugarov, Sergey Yu., Chochol, Drahomir, Krushevska, Viktoriia, Sekeras, Matej, Pikalova, Olga, Sabo, Richard, Dubovsky, Pavol A., Kudzej, Igor, Ulowetz, Joseph, Dvorak, Shawn, Stone, Geoff, Tordai, Tamas, Dubois, Franky, Logie, Ludwig, Rau, Steve, Vanaverbeke, Siegfried, Vanmunster, Tonny, Oksanen, Arto, Maeda, Yutaka, Kasai, Kiyoshi, Katysheva, Natalia, Morelle, Etienne, Neustroev, Vitaly V., and Sjoberg, George

Subjects
Astrophysics - Solar and Stellar Astrophysics
Abstract

We observed RZ LMi, which is renowned for the extremely (~19d) short supercycle and is a member of a small, unusual class of cataclysmic variables called ER UMa-type dwarf novae, in 2013 and 2016. In 2016, the supercycles of this object substantially lengthened in comparison to the previous measurements to 35, 32, 60d for three consecutive superoutbursts. We consider that the object virtually experienced a transition to the novalike state (permanent superhumper). This observed behavior extremely well reproduced the prediction of the thermal-tidal instability model. We detected a precursor in the 2016 superoutburst and detected growing (stage A) superhumps with a mean period of 0.0602(1)d in 2016 and in 2013. Combined with the period of superhumps immediately after the superoutburst, the mass ratio is not as small as in WZ Sge-type dwarf novae, having orbital periods similar to RZ LMi. By using least absolute shrinkage and selection operator (Lasso) two-dimensional power spectra, we detected possible negative superhumps with a period of 0.05710(1)d. We estimated the orbital period of 0.05792d, which suggests a mass ratio of 0.105(5). This relatively large mass ratio is even above ordinary SU UMa-type dwarf novae, and it is also possible that the exceptionally high mass-transfer rate in RZ LMi may be a result of a stripped core evolved secondary which are evolving toward an AM CVn-type object., Comment: 14 pages, 14 figures, accepted for publication in PASJ; includes Supplementary_draft_aph.pdf with somewhat degraded figures

Published
2016
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11. Return of the King: Time-Series Photometry of FO Aquarii's Initial Recovery from its Unprecedented 2016 Low State

Author

Littlefield, Colin, Garnavich, Peter, Kennedy, Mark R., Aadland, Erin, Terndrup, Donald M., Calhoun, Grace V., Callanan, Paul, Abe, Lyu, Bendjoya, Philippe, Rivet, Jean-Pierre, Vernet, David, Devogele, Maxime, Shappee, Benjamin, Holoien, Thomas, Heras, Teofilo Arranz, Bonnardeau, Michel, Cook, Michael, Coulter, Daniel, Debackere, Andre, Dvorak, Shawn, Foster, James R., Goff, William, Hambsch, Franz-Josef, Harris, Barbara, Myers, Gordon, Nelson, Peter, Popov, Velimir, Solomon, Rob, Stein, William L., Stone, Geoff, and Vietje, Brad

Subjects
Astrophysics - Solar and Stellar Astrophysics
Abstract

In 2016 May, the intermediate polar FO~Aqr was detected in a low state for the first time in its observational history. We report time-resolved photometry of the system during its initial recovery from this faint state. Our data, which includes high-speed photometry with cadences of just 2 sec, shows the existence of very strong periodicities at 22.5 min and 11.26 min, equivalent to the spin-orbit beat frequency and twice its value, respectively. A pulse at the spin frequency is also present but at a much lower amplitude than is normally observed in the bright state. By comparing our power spectra with theoretical models, we infer that a substantial amount of accretion was stream-fed during our observations, in contrast to the disk-fed accretion that dominates the bright state. In addition, we find that FO~Aqr's rate of recovery has been unusually slow in comparison to rates of recovery seen in other magnetic cataclysmic variables, with an $e$-folding time of 115$\pm7$ days. The recovery also shows irregular variations in the median brightness of as much as 0.2~mag over a 10-day span. Finally, we show that the arrival times of the spin pulses are dependent upon the system's overall brightness., Comment: Accepted for publication at ApJ. The paper now includes ASAS-SN observations of what we believe is the initial decline from the high state. New co-authors have been added

Published
2016
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12. Survey of Period Variations of Superhumps in SU UMa-Type Dwarf Novae. VIII: The Eighth Year (2015-2016)

Author

Kato, Taichi, Hambsch, Franz-Josef, Monard, Berto, Vanmunster, Tonny, Maeda, Yutaka, Miller, Ian, Itoh, Hiroshi, Kiyota, Seiichiro, Isogai, Keisuke, Kimura, Mariko, Imada, Akira, Tordai, Tamas, Akazawa, Hidehiko, Tanabe, Kenji, Otani, Noritoshi, Ogi, Minako, Ando, Kazuko, Takigawa, Naoki, Dubovsky, Pavol A., Kudzej, Igor, Shugarov, Sergey Yu., Katysheva, Natalia, Golysheva, Polina, Gladilina, Natalia, Chochol, Drahomir, Starr, Peter, Kasai, Kiyoshi, Pickard, Roger D., de Miguel, Enrique, Kojiguchi, Naoto, Sugiura, Yuki, Fukushima, Daiki, Yamada, Eiji, Uto, Yusuke, Kamibetsunawa, Taku, Tatsumi, Taiki, Takeda, Nao, Matsumoto, Katsura, Cook, Lewis M., Pavlenko, Elena P., Babina, Julia V., Pit, Nikolaj V., Antonyuk, Oksana I., Antonyuk, Kirill A., Sosnovskij, Aleksei A., Baklanov, Aleksei V., Kafka, Stella, Stein, William, Voloshina, Irina B., Ruiz, Javier, Sabo, Richard, Dvorak, Shawn, Stone, Geoff, Andreev, Maksim V., Antipin, Sergey V., Zubareva, Alexandra M., Zaostrojnykh, Anna M., Richmond, Michael, Shears, Jeremy, Dubois, Franky, Logie, Ludwig, Rau, Steve, Vanaverbeke, Siegfried, Simon, Andrei, Oksanen, Arto, Goff, William N., Bolt, Greg, Debski, Bartomiej, Kochanek, Christopher S., Shappee, Benjamin, Stanek, Krzysztof Z., Prieto, Jose L., Stubbings, Rod, Muyllaert, Eddy, Hiraga, Mitsutaka, Horie, Tsuneo, Schmeer, Patrick, and Hirosawa, Kenji

Subjects
Astrophysics - Solar and Stellar Astrophysics
Abstract

Continuing the project described by Kato et al. (2009, arXiv:0905.1757), we collected times of superhump maxima for 128 SU UMa-type dwarf novae observed mainly during the 2015-2016 season and characterized these objects. The data have improved the distribution of orbital periods, the relation between the orbital period and the variation of superhumps, the relation between period variations and the rebrightening type in WZ Sge-type objects. Coupled with new measurements of mass ratios using growing stages of superhumps, we now have a clearer and statistically greatly improved evolutionary path near the terminal stage of evolution of cataclysmic variables. Three objects (V452 Cas, KK Tel, ASASSN-15cl) appear to have slowly growing superhumps, which is proposed to reflect the slow growth of the 3:1 resonance near the stability border. ASASSN-15sl, ASASSN-15ux, SDSS J074859.55+312512.6 and CRTS J200331.3-284941 are newly identified eclipsing SU UMa-type (or WZ Sge-type) dwarf novae. ASASSN-15cy has a short (~0.050 d) superhump period and appears to belong to EI Psc-type objects with compact secondaries having an evolved core. ASASSN-15gn, ASASSN-15hn, ASASSN-15kh and ASASSN-16bu are candidate period bouncers with superhump periods longer than 0.06 d. We have newly obtained superhump periods for 79 objects and 13 orbital periods, including periods from early superhumps. In order that the future observations will be more astrophysically beneficial and rewarding to observers, we propose guidelines how to organize observations of various superoutbursts., Comment: 123 pages, 162 figures, 119 tables, accepted for publication in PASJ (including supplementary information)

Published
2016
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15. Aotearoa New Zealand national evaluation conference

Author

Schumacher, Joseph, Mujumdar, Debi, Howard, Christina, Stone, Geoff, and Davie, Salena

Subjects
New Zealand -- Conferences, meetings and seminars, Social change -- Analysis -- Conferences, meetings and seminars, Government, Political science
Abstract

The third annual Aotearoa New Zealand National Evaluation Conference, sponsored by the Auckland Evaluation Group and held in Taupo from 31 July to 2 August 2006, attracted over 50 participants [...]

Published
2006

16. ASASSN-18aan: An eclipsing SU UMa-type cataclysmic variable with a 3.6-hr orbital period and a late G-type secondary star

Author

Wakamatsu, Yasuyuki, primary, Thorstensen, John R, additional, Kojiguchi, Naoto, additional, Isogai, Keisuke, additional, Kimura, Mariko, additional, Ohnishi, Ryuhei, additional, Kato, Taichi, additional, Itoh, Hiroshi, additional, Sugiura, Yuki, additional, Sumiya, Sho, additional, Matsumoto, Hanami, additional, Ito, Daiki, additional, Nikai, Kengo, additional, Akitaya, Hiroshi, additional, Ishioka, Chihiro, additional, Oide, Kohei, additional, Kanai, Takahiro, additional, Uzawa, Yoshinori, additional, Oasa, Yumiko, additional, Tordai, Tamás, additional, Vanmunster, Tonny, additional, Shugarov, Sergey Yu, additional, Yamanaka, Masayuki, additional, Sasada, Mahito, additional, Takagi, Kengo, additional, Nishinaka, Yuki, additional, Yamazaki, Yuina, additional, Otsubo, Ikki, additional, Nakaoka, Tatsuya, additional, Murata, Katsuhiro L, additional, Ohsawa, Ryou, additional, Morita, Masahiro, additional, Ichiki, Makoto, additional, Dufoer, Sjoerd, additional, Mizutani, Masanori, additional, Horiuchi, Takashi, additional, Tozuka, Miyako, additional, Takayama, Masaki, additional, Ohshima, Tomohito, additional, Saito, Tomoki, additional, Dubovsky, Pavol A, additional, Stone, Geoff, additional, Miller, Ian, additional, and Nogami, Daisaku, additional

Published
2021
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17. Survey of period variations of superhumps in SU UMa-type dwarf novae. X. The tenth year (2017)

Author

Kato, Taichi, primary, Isogai, Keisuke, additional, Wakamatsu, Yasuyuki, additional, Hambsch, Franz-Josef, additional, Itoh, Hiroshi, additional, Tordai, Tamás, additional, Vanmunster, Tonny, additional, Dubovsky, Pavol A, additional, Kudzej, Igor, additional, Medulka, Tomáš, additional, Kimura, Mariko, additional, Ohnishi, Ryuhei, additional, Monard, Berto, additional, Pavlenko, Elena P, additional, Antonyuk, Kirill A, additional, Pit, Nikolaj V, additional, Antonyuk, Oksana I, additional, Babina, Julia V, additional, Baklanov, Aleksei V, additional, Sosnovskij, Aleksei A, additional, Pickard, Roger D, additional, Miller, Ian, additional, Maeda, Yutaka, additional, de Miguel, Enrique, additional, Brincat, Stephen M, additional, Licchelli, Domenico, additional, Cook, Lewis M, additional, Shugarov, Sergey Yu, additional, Zaostrojnykh, Anna M, additional, Chochol, Drahomir, additional, Golysheva, Polina, additional, Katysheva, Natalia, additional, Zubareva, Alexandra M, additional, Stone, Geoff, additional, Kasai, Kiyoshi, additional, Starr, Peter, additional, Littlefield, Colin, additional, Kiyota, Seiichiro, additional, Andreev, Maksim V, additional, Sergeev, Alexandr V, additional, Ruiz, Javier, additional, Myers, Gordon, additional, Simon, Andrii O, additional, Vasylenko, Volodymyr V, additional, Soldán, Francisco, additional, Ögmen, Yenal, additional, Nakajima, Kazuhiro, additional, Nelson, Peter, additional, Masi, Gianluca, additional, Menzies, Kenneth, additional, Sabo, Richard, additional, Bolt, Greg, additional, Dvorak, Shawn, additional, Stanek, Krzysztof Z, additional, Shields, Joseph V, additional, Kochanek, Christopher S, additional, Holoien, Thomas W-S, additional, Shappee, Benjamin, additional, Prieto, José L, additional, Kojima, Tadashi, additional, Nishimura, Hideo, additional, Kaneko, Shizuo, additional, Fujikawa, Shigehisa, additional, Stubbings, Rod, additional, Muyllaert, Eddy, additional, Poyner, Gary, additional, Moriyama, Masayuki, additional, Maehara, Hiroyuki, additional, Schmeer, Patrick, additional, and Denisenko, Denis, additional

Published
2020
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20. The First Post-Kepler Brightness Dips of KIC 8462852

Author

Boyajian, Tabetha. S., Alonso, Roi, Ammerman, Alex, Armstrong, David, Ramos, A. Asensio, Barkaoui, K., Beatty, Thomas G., Benkhaldoun, Z., Benni, Paul, Bentley, Rory O., Berdyugin, Andrei, Berdyugina, Svetlana, Bergeron, Serge, Bieryla, Allyson, Blain, Michaela G., Blanco, Alicia Capetillo, Bodman, Eva H. L., Boucher, Anne, Bradley, Mark, Brincat, Stephen M., Brink, Thomas G., Briol, John, Brown, David J. A., Budaj, J., Burdanov, A., Cale, B., Carbo, Miguel Aznar, Garcia, R. Castillo, Clark, Wendy J., Clayton, Geoffrey C., Clem, James L., Coker, Phillip H., Cook, Evan M., Copperwheat, Chris M., Curtis, J. L., Cutri, R. M., Cseh, B., Cynamon, C. H., Daniels, Alex J., Davenport, James R. A., Deeg, Hans J., De Lorenzo, Roberto, De Jaeger, Thomas, Desrosiers, Jean-Bruno, Dolan, John, Dowhos, D. J., Dubois, Franky, Durkee, R., Dvorak, Shawn, Easley, Lynn, Edwards, N., Ellis, Tyler G., Erdelyi, Emery, Ertel, Steve, Farfan, Rafael. G., Farihi, J., Filippenko, Alexei V., Foxell, Emma, Gandolfi, Davide, Garcia, Faustino, Giddens, F., Gillon, M., Gonzalez-Carballo, Juan-Luis, Gonzalez-Fernandez, C., Hernandez, J. I. Gonzalez, Graham, Keith A., Greene, Kenton A., Gregorio, J., Hallakoun, Na'ama, Hanyecz, Otto, Harp, G. R., Henry, Gregory W., Herrero, E., Hildbold, Caleb F., Hinzel, D., Holgado, G., Ignacz, Bernadett, Ilyin, Ilya, Ivanov, Valentin D., Jehin, E., Jermak, Helen E., Johnston, Steve, Kafka, S., Kalup, Csilla, Kardasis, Emmanuel, Kaspi, Shai, Kennedy, Grant M., Kiefer, F., Kielty, C. L., Kessler, Dennis, Kiiskinen, H., Killestein, T. L., King, Ronald A., Kollar, V., Korhonen, H., Kotnik, C., Konyves-Toth, Reka, Kriskovics, Levente, Krumm, Nathan, Krushinsky, Vadim, Kundra, E., Lachapelle, Francois-Rene, LaCourse, D., Lake, P., Lam, Kristine, Lamb, Gavin P., Lane, Dave, Lau, Marie Wingyee, Lewin, Pablo, Lintott, Chris, Lisse, Carey, Logie, Ludwig, Longeard, Nicolas, Villanueva, M. Lopez, Ludington, E. Whit, Mainzer, A., Malo, Lison, Maloney, Chris, Mann, A., Mantero, A., Marengo, Massimo, Marchant, Jon, Gonzalez, M. J. Martinez, Masiero, Joseph R., Mauerhan, Jon C., McCormac, James, McNeely, Aaron, Meng, Huan Y. A., Miller, Mike, Molnar, Lawrence A., Morales, J. C., Morris, Brett M., Muterspaugh, Matthew W., Nespral, David, Nugent, C. R., Nugent, Katherine M., Odasso, A., O'Keeffe, Derek, Oksanen, A., O'Meara, John M., Ordasi, Andras, Osborn, Hugh, Ott, John J., Parks, J. R., Perez, Diego Rodriguez, Petriew, Vance, Pickard, R., Pal, Andras, Plavchan, P., Pollacco, Don, Nunez, F. Pozo, Pozuelos, F. J., Rau, Steve, Redfield, Seth, Relles, Howard, Ribas, Ignasi, Richards, Jon, Saario, Joonas L. O., Safron, Emily J., Sallai, J. Martin, Sarneczky, Krisztian, Schaefer, Bradley E., Schumer, Clea F., Schwartzendruber, Madison, Siegel, Michael H., Siemion, Andrew P. V., Simmons, Brooke D., Simon, Joshua D., Simon-Diaz, S., Sitko, Michael L., Socas-Navarro, Hector, Sodor, A., Starkey, Donn, Steele, Iain A., Stone, Geoff, Strassmeier, Klaus G., Street, R. A., Sullivan, Tricia, Suomela, J., Swift, J. J., Szabo, Gyula M., Szabo, Robert, Szakats, Robert, Szalai, Tamas, Tanner, Angelle M., Toledo-Padron, B., Tordai, Tamas, Triaud, Amaury H. M. J., Turner, Jake D., Ulowetz, Joseph H., Urbanik, Marian, Vanaverbeke, Siegfried, Vanderburg, Andrew, Vida, Krisztian, Vietje, Brad P., Vinko, Jozsef, Von Braun, K., Waagen, Elizabeth O., Walsh, Dan, Watson, Christopher A., Weir, R. C., Wenzel, Klaus, Plaza, C. Westendorp, Williamson, Michael W., Wright, Jason T., Wyatt, M. C., Zheng, WeiKang, Zsidi, Gabriella, Boyajian, Tabetha. S., Alonso, Roi, Ammerman, Alex, Armstrong, David, Ramos, A. Asensio, Barkaoui, K., Beatty, Thomas G., Benkhaldoun, Z., Benni, Paul, Bentley, Rory O., Berdyugin, Andrei, Berdyugina, Svetlana, Bergeron, Serge, Bieryla, Allyson, Blain, Michaela G., Blanco, Alicia Capetillo, Bodman, Eva H. L., Boucher, Anne, Bradley, Mark, Brincat, Stephen M., Brink, Thomas G., Briol, John, Brown, David J. A., Budaj, J., Burdanov, A., Cale, B., Carbo, Miguel Aznar, Garcia, R. Castillo, Clark, Wendy J., Clayton, Geoffrey C., Clem, James L., Coker, Phillip H., Cook, Evan M., Copperwheat, Chris M., Curtis, J. L., Cutri, R. M., Cseh, B., Cynamon, C. H., Daniels, Alex J., Davenport, James R. A., Deeg, Hans J., De Lorenzo, Roberto, De Jaeger, Thomas, Desrosiers, Jean-Bruno, Dolan, John, Dowhos, D. J., Dubois, Franky, Durkee, R., Dvorak, Shawn, Easley, Lynn, Edwards, N., Ellis, Tyler G., Erdelyi, Emery, Ertel, Steve, Farfan, Rafael. G., Farihi, J., Filippenko, Alexei V., Foxell, Emma, Gandolfi, Davide, Garcia, Faustino, Giddens, F., Gillon, M., Gonzalez-Carballo, Juan-Luis, Gonzalez-Fernandez, C., Hernandez, J. I. Gonzalez, Graham, Keith A., Greene, Kenton A., Gregorio, J., Hallakoun, Na'ama, Hanyecz, Otto, Harp, G. R., Henry, Gregory W., Herrero, E., Hildbold, Caleb F., Hinzel, D., Holgado, G., Ignacz, Bernadett, Ilyin, Ilya, Ivanov, Valentin D., Jehin, E., Jermak, Helen E., Johnston, Steve, Kafka, S., Kalup, Csilla, Kardasis, Emmanuel, Kaspi, Shai, Kennedy, Grant M., Kiefer, F., Kielty, C. L., Kessler, Dennis, Kiiskinen, H., Killestein, T. L., King, Ronald A., Kollar, V., Korhonen, H., Kotnik, C., Konyves-Toth, Reka, Kriskovics, Levente, Krumm, Nathan, Krushinsky, Vadim, Kundra, E., Lachapelle, Francois-Rene, LaCourse, D., Lake, P., Lam, Kristine, Lamb, Gavin P., Lane, Dave, Lau, Marie Wingyee, Lewin, Pablo, Lintott, Chris, Lisse, Carey, Logie, Ludwig, Longeard, Nicolas, Villanueva, M. Lopez, Ludington, E. Whit, Mainzer, A., Malo, Lison, Maloney, Chris, Mann, A., Mantero, A., Marengo, Massimo, Marchant, Jon, Gonzalez, M. J. Martinez, Masiero, Joseph R., Mauerhan, Jon C., McCormac, James, McNeely, Aaron, Meng, Huan Y. A., Miller, Mike, Molnar, Lawrence A., Morales, J. C., Morris, Brett M., Muterspaugh, Matthew W., Nespral, David, Nugent, C. R., Nugent, Katherine M., Odasso, A., O'Keeffe, Derek, Oksanen, A., O'Meara, John M., Ordasi, Andras, Osborn, Hugh, Ott, John J., Parks, J. R., Perez, Diego Rodriguez, Petriew, Vance, Pickard, R., Pal, Andras, Plavchan, P., Pollacco, Don, Nunez, F. Pozo, Pozuelos, F. J., Rau, Steve, Redfield, Seth, Relles, Howard, Ribas, Ignasi, Richards, Jon, Saario, Joonas L. O., Safron, Emily J., Sallai, J. Martin, Sarneczky, Krisztian, Schaefer, Bradley E., Schumer, Clea F., Schwartzendruber, Madison, Siegel, Michael H., Siemion, Andrew P. V., Simmons, Brooke D., Simon, Joshua D., Simon-Diaz, S., Sitko, Michael L., Socas-Navarro, Hector, Sodor, A., Starkey, Donn, Steele, Iain A., Stone, Geoff, Strassmeier, Klaus G., Street, R. A., Sullivan, Tricia, Suomela, J., Swift, J. J., Szabo, Gyula M., Szabo, Robert, Szakats, Robert, Szalai, Tamas, Tanner, Angelle M., Toledo-Padron, B., Tordai, Tamas, Triaud, Amaury H. M. J., Turner, Jake D., Ulowetz, Joseph H., Urbanik, Marian, Vanaverbeke, Siegfried, Vanderburg, Andrew, Vida, Krisztian, Vietje, Brad P., Vinko, Jozsef, Von Braun, K., Waagen, Elizabeth O., Walsh, Dan, Watson, Christopher A., Weir, R. C., Wenzel, Klaus, Plaza, C. Westendorp, Williamson, Michael W., Wright, Jason T., Wyatt, M. C., Zheng, WeiKang, and Zsidi, Gabriella

Published
2018

21. On the nature of long-period dwarf novae with rare and low-amplitude outbursts

Author

Kimura, Mariko, primary, Kato, Taichi, additional, Maehara, Hiroyuki, additional, Ishioka, Ryoko, additional, Monard, Berto, additional, Nakajima, Kazuhiro, additional, Stone, Geoff, additional, Pavlenko, Elena P, additional, Antonyuk, Oksana I, additional, Pit, Nikolai V, additional, Sosnovskij, Aleksei A, additional, Katysheva, Natalia, additional, Richmond, Michael, additional, Michel, Raúl, additional, Matsumoto, Katsura, additional, Kojiguchi, Naoto, additional, Sugiura, Yuki, additional, Tei, Shihei, additional, Yamamura, Kenta, additional, Cook, Lewis M, additional, Sabo, Richard, additional, Miller, Ian, additional, Goff, William, additional, Kiyota, Seiichiro, additional, Shugarov, Sergey Yu, additional, Golysheva, Polina, additional, Vozyakova, Olga, additional, Brincat, Stephen M, additional, Itoh, Hiroshi, additional, Tordai, Tamás, additional, Littlefield, Colin, additional, Pickard, Roger D, additional, Tanabe, Kenji, additional, Kinugasa, Kenzo, additional, Honda, Satoshi, additional, Taguchi, Hikaru, additional, Hashimoto, Osamu, additional, and Nogami, Daisaku, additional

Published
2018
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22. ASASSN-16dt and ASASSN-16hg: Promising candidate period bouncers

Author

Kimura, Mariko, primary, Isogai, Keisuke, additional, Kato, Taichi, additional, Taguchi, Kenta, additional, Wakamatsu, Yasuyuki, additional, Hambsch, Franz-Josef, additional, Monard, Berto, additional, Myers, Gordon, additional, Dvorak, Shawn, additional, Starr, Peter, additional, Brincat, Stephen M, additional, de Miguel, Enrique, additional, Ulowetz, Joseph, additional, Itoh, Hiroshi, additional, Stone, Geoff, additional, and Nogami, Daisaku, additional

Published
2018
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23. The First Post- Kepler Brightness Dips of KIC 8462852

Author

Boyajian, Tabetha. S., primary, Alonso, Roi, additional, Ammerman, Alex, additional, Armstrong, David, additional, Ramos, A. Asensio, additional, Barkaoui, K., additional, Beatty, Thomas G., additional, Benkhaldoun, Z., additional, Benni, Paul, additional, O. Bentley, Rory, additional, Berdyugin, Andrei, additional, Berdyugina, Svetlana, additional, Bergeron, Serge, additional, Bieryla, Allyson, additional, Blain, Michaela G., additional, Blanco, Alicia Capetillo, additional, Bodman, Eva H. L., additional, Boucher, Anne, additional, Bradley, Mark, additional, Brincat, Stephen M., additional, Brink, Thomas G., additional, Briol, John, additional, Brown, David J. A., additional, Budaj, J., additional, Burdanov, A., additional, Cale, B., additional, Carbo, Miguel Aznar, additional, García, R. Castillo, additional, Clark, Wendy J, additional, Clayton, Geoffrey C., additional, Clem, James L., additional, Coker, Phillip H, additional, Cook, Evan M., additional, Copperwheat, Chris M., additional, Curtis, J. L., additional, Cutri, R. M., additional, Cseh, B., additional, Cynamon, C. H., additional, Daniels, Alex J., additional, Davenport, James R. A., additional, Deeg, Hans J., additional, Lorenzo, Roberto De, additional, Jaeger, Thomas de, additional, Desrosiers, Jean-Bruno, additional, Dolan, John, additional, Dowhos, D. J., additional, Dubois, Franky, additional, Durkee, R., additional, Dvorak, Shawn, additional, Easley, Lynn, additional, Edwards, N., additional, Ellis, Tyler G., additional, Erdelyi, Emery, additional, Ertel, Steve, additional, Farfán, Rafael. G., additional, Farihi, J., additional, Filippenko, Alexei V., additional, Foxell, Emma, additional, Gandolfi, Davide, additional, Garcia, Faustino, additional, Giddens, F., additional, Gillon, M., additional, González-Carballo, Juan-Luis, additional, González-Fernández, C., additional, Hernández, J. I. González, additional, Graham, Keith A., additional, Greene, Kenton A., additional, Gregorio, J., additional, Hallakoun, Na’ama, additional, Hanyecz, Ottó, additional, Harp, G. R., additional, Henry, Gregory W., additional, Herrero, E., additional, Hildbold, Caleb F., additional, Hinzel, D., additional, Holgado, G., additional, Ignácz, Bernadett, additional, Ilyin, Ilya, additional, Ivanov, Valentin D., additional, Jehin, E., additional, Jermak, Helen E., additional, Johnston, Steve, additional, Kafka, S., additional, Kalup, Csilla, additional, Kardasis, Emmanuel, additional, Kaspi, Shai, additional, Kennedy, Grant M., additional, Kiefer, F., additional, Kielty, C. L., additional, Kessler, Dennis, additional, Kiiskinen, H., additional, Killestein, T. L., additional, King, Ronald A., additional, Kollar, V., additional, Korhonen, H., additional, Kotnik, C., additional, Könyves-Tóth, Réka, additional, Kriskovics, Levente, additional, Krumm, Nathan, additional, Krushinsky, Vadim, additional, Kundra, E., additional, Lachapelle, Francois-Rene, additional, LaCourse, D., additional, Lake, P., additional, Lam, Kristine, additional, Lamb, Gavin P., additional, Lane, Dave, additional, Lau, Marie Wingyee, additional, Lewin, Pablo, additional, Lintott, Chris, additional, Lisse, Carey, additional, Logie, Ludwig, additional, Longeard, Nicolas, additional, Villanueva, M. Lopez, additional, Ludington, E. Whit, additional, Mainzer, A., additional, Malo, Lison, additional, Maloney, Chris, additional, Mann, A., additional, Mantero, A., additional, Marengo, Massimo, additional, Marchant, Jon, additional, Martínez González, M. J., additional, Masiero, Joseph R., additional, Mauerhan, Jon C., additional, McCormac, James, additional, McNeely, Aaron, additional, Meng, Huan Y. A., additional, Miller, Mike, additional, Molnar, Lawrence A., additional, Morales, J. C., additional, Morris, Brett M., additional, Muterspaugh, Matthew W., additional, Nespral, David, additional, Nugent, C. R., additional, Nugent, Katherine M., additional, Odasso, A., additional, O’Keeffe, Derek, additional, Oksanen, A., additional, O’Meara, John M., additional, Ordasi, András, additional, Osborn, Hugh, additional, Ott, John J., additional, Parks, J. R., additional, Perez, Diego Rodriguez, additional, Petriew, Vance, additional, Pickard, R, additional, Pál, András, additional, Plavchan, P., additional, Pollacco, Don, additional, Nuñez, F. Pozo, additional, J. Pozuelos, F., additional, Rau, Steve, additional, Redfield, Seth, additional, Relles, Howard, additional, Ribas, Ignasi, additional, Richards, Jon, additional, Saario, Joonas L. O., additional, Safron, Emily J., additional, Sallai, J. Martin, additional, Sárneczky, Krisztián, additional, Schaefer, Bradley E., additional, Schumer, Clea F., additional, Schwartzendruber, Madison, additional, Siegel, Michael H., additional, Siemion, Andrew P. V., additional, Simmons, Brooke D., additional, Simon, Joshua D., additional, Simón-Díaz, S., additional, Sitko, Michael L., additional, Socas-Navarro, Hector, additional, Sódor, Á., additional, Starkey, Donn, additional, Steele, Iain A., additional, Stone, Geoff, additional, Strassmeier, Klaus G., additional, Street, R. A., additional, Sullivan, Tricia, additional, Suomela, J., additional, Swift, J. J., additional, Szabó, Gyula M., additional, Szabó, Róbert, additional, Szakáts, Róbert, additional, Szalai, Tamás, additional, Tanner, Angelle M., additional, Toledo-Padrón, B., additional, Tordai, Tamás, additional, Triaud, Amaury H. M. J., additional, Turner, Jake D., additional, Ulowetz, Joseph H., additional, Urbanik, Marian, additional, Vanaverbeke, Siegfried, additional, Vanderburg, Andrew, additional, Vida, Krisztián, additional, Vietje, Brad P., additional, Vinkó, József, additional, Braun, K. von, additional, Waagen, Elizabeth O., additional, Walsh, Dan, additional, Watson, Christopher A., additional, Weir, R. C., additional, Wenzel, Klaus, additional, Plaza, C. Westendorp, additional, Williamson, Michael W., additional, Wright, Jason T., additional, Wyatt, M. C., additional, Zheng, WeiKang, additional, and Zsidi, Gabriella, additional

Published
2018
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24. OT J002656.6+284933 (CSS101212:002657+284933): an SU UMa-type dwarf nova with the longest superhump period

Author

Ministry of Education, Culture, Sports, Science and Technology (Japan), VEGA Agency (Slovakia), Russian Foundation for Basic Research, Kato, Taichi, Tordai, Tamás, Littlefield, Colin, Kasai, Kiyoshi, Shugarov, Sergey Yu., Katysheva, Natalia, Zaostrojnykh, Anna M., Pickard, Roger D., Miguel, Enrique de, Antonyuk, Kirill, Antonyuk, Oksana, Pavlenko, Elena P., Pit, Nikolai, Itoh, Hiroshi, Ruiz, Javier, Isogai, Keisuke, Kimura, Mariko, Wakamatsu, Yasuyuki, Vanmunster, Tonny, Stone, Geoff, Ministry of Education, Culture, Sports, Science and Technology (Japan), VEGA Agency (Slovakia), Russian Foundation for Basic Research, Kato, Taichi, Tordai, Tamás, Littlefield, Colin, Kasai, Kiyoshi, Shugarov, Sergey Yu., Katysheva, Natalia, Zaostrojnykh, Anna M., Pickard, Roger D., Miguel, Enrique de, Antonyuk, Kirill, Antonyuk, Oksana, Pavlenko, Elena P., Pit, Nikolai, Itoh, Hiroshi, Ruiz, Javier, Isogai, Keisuke, Kimura, Mariko, Wakamatsu, Yasuyuki, Vanmunster, Tonny, and Stone, Geoff

Abstract

We observed the 2016 outburst of OT J002656.6+284933 (CSS101212:002657+284933) and found that it has the longest recorded [0.13225(1) d on average] superhumps among SU UMa-type dwarf novae. The object is the third known SU UMa-type dwarf nova above the period gap. The outburst, however, was unlike ordinary long-period SU UMa-type dwarf novae in that it showed two post-outburst rebrightenings. It showed superhump evolution similar to short-period SU UMa-type dwarf novae. We could constrain the mass ratio to less than 0.15 (most likely between 0.10 and 0.15) by using superhump periods in the early and post-superoutburst stages. These results suggest the possibility that OT J002656.6+284933 has an anomalously undermassive secondary and it should have followed a different evolutionary track from the standard one.

Published
2017

25. ASASSN-16eg: New candidate for a long-period WZ Sge-type dwarf nova

Author

Wakamatsu, Yasuyuki, primary, Isogai, Keisuke, additional, Kimura, Mariko, additional, Kato, Taichi, additional, Vanmunster, Tonny, additional, Stone, Geoff, additional, Tordai, Tamás, additional, Richmond, Michael, additional, Miller, Ian, additional, Oksanen, Arto, additional, Itoh, Hiroshi, additional, Akazawa, Hidehiko, additional, Kiyota, Seiichiro, additional, de Miguel, Enrique, additional, Pavlenko, Elena P., additional, Antonyuk, Kirill A., additional, Antonyuk, Oksana I., additional, Neustroev, Vitaly V., additional, Sjoberg, George, additional, Dubovsky, Pavol A., additional, Pickard, Roger D., additional, and Nogami, Daisaku, additional

Published
2017
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26. Survey of period variations of superhumps in SU UMa-type dwarf novae. IX. The ninth year (2016–2017)

Author

Kato, Taichi, primary, Isogai, Keisuke, additional, Hambsch, Franz-Josef, additional, Vanmunster, Tonny, additional, Itoh, Hiroshi, additional, Monard, Berto, additional, Tordai, Tamás, additional, Kimura, Mariko, additional, Wakamatsu, Yasuyuki, additional, Kiyota, Seiichiro, additional, Miller, Ian, additional, Starr, Peter, additional, Kasai, Kiyoshi, additional, Shugarov, Sergey Yu., additional, Chochol, Drahomir, additional, Katysheva, Natalia, additional, Zaostrojnykh, Anna M., additional, Sekeráš, Matej, additional, Kuznyetsova, Yuliana G., additional, Kalinicheva, Eugenia S., additional, Golysheva, Polina, additional, Krushevska, Viktoriia, additional, Maeda, Yutaka, additional, Dubovsky, Pavol A., additional, Kudzej, Igor, additional, Pavlenko, Elena P., additional, Antonyuk, Kirill A., additional, Pit, Nikolaj V., additional, Sosnovskij, Aleksei A., additional, Antonyuk, Oksana I., additional, Baklanov, Aleksei V., additional, Pickard, Roger D., additional, Kojiguchi, Naoto, additional, Sugiura, Yuki, additional, Tei, Shihei, additional, Yamamura, Kenta, additional, Matsumoto, Katsura, additional, Ruiz, Javier, additional, Stone, Geoff, additional, Cook, Lewis M., additional, de Miguel, Enrique, additional, Akazawa, Hidehiko, additional, Goff, William N., additional, Morelle, Etienne, additional, Kafka, Stella, additional, Littlefield, Colin, additional, Bolt, Greg, additional, Dubois, Franky, additional, Brincat, Stephen M., additional, Maehara, Hiroyuki, additional, Sakanoi, Takeshi, additional, Kagitani, Masato, additional, Imada, Akira, additional, Voloshina, Irina B., additional, Andreev, Maksim V., additional, Sabo, Richard, additional, Richmond, Michael, additional, Rodda, Tony, additional, Nelson, Peter, additional, Nazarov, Sergey, additional, Mishevskiy, Nikolay, additional, Myers, Gordon, additional, Denisenko, Denis, additional, Stanek, Krzysztof Z., additional, Shields, Joseph V., additional, Kochanek, Christopher S., additional, Holoien, Thomas W.-S., additional, Shappee, Benjamin, additional, Prieto, José L., additional, Itagaki, Koh-ichi, additional, Nishiyama, Koichi, additional, Kabashima, Fujio, additional, Stubbings, Rod, additional, Schmeer, Patrick, additional, Muyllaert, Eddy, additional, Horie, Tsuneo, additional, Shears, Jeremy, additional, Poyner, Gary, additional, and Moriyama, Masayuki, additional

Published
2017
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27. Erratum: OT J002656.6+284933 (CSS101212:002657+284933): an SUUMa-type dwarf nova with the longest superhump period

Author

Kato, Taichi, primary, Tordai, Tamás, additional, Littlefield, Colin, additional, Kasai, Kiyoshi, additional, Shugarov, Sergey Yu., additional, Katysheva, Natalia, additional, Zaostrojnykh, Anna M., additional, Pickard, Roger D., additional, de Miguel, Enrique, additional, Antonyuk, Kirill, additional, Antonyuk, Oksana, additional, Pavlenko, Elena P., additional, Pit, Nikolai, additional, Itoh, Hiroshi, additional, Ruiz, Javier, additional, Isogai, Keisuke, additional, Kimura, Mariko, additional, Wakamatsu, Yasuyuki, additional, Vanmunster, Tonny, additional, and Stone, Geoff, additional

Published
2017
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28. OT J002656.6+284933 (CSS101212:002657+284933): an SU UMa-type dwarf nova with the longest superhump period

Author

Kato, Taichi, primary, Tordai, Tamás, additional, Littlefield, Colin, additional, Kasai, Kiyoshi, additional, Shugarov, Sergey Yu., additional, Katysheva, Natalia, additional, Zaostrojnykh, Anna M., additional, Pickard, Roger D., additional, de Miguel, Enrique, additional, Antonyuk, Kirill, additional, Antonyuk, Oksana, additional, Pavlenko, Elena P., additional, Pit, Nikolai, additional, Itoh, Hiroshi, additional, Ruiz, Javier, additional, Isogai, Keisuke, additional, Kimura, Mariko, additional, Wakamatsu, Yasuyuki, additional, Vanmunster, Tonny, additional, and Stone, Geoff, additional

Published
2017
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29. RETURN OF THE KING: TIME-SERIES PHOTOMETRY OF FO AQUARII’S INITIAL RECOVERY FROM ITS UNPRECEDENTED 2016 LOW STATE

Author

Littlefield, Colin, primary, Garnavich, Peter, additional, Kennedy, Mark R., additional, Aadland, Erin, additional, Terndrup, Donald M., additional, Calhoun, Grace V., additional, Callanan, Paul, additional, Abe, Lyu, additional, Bendjoya, Philippe, additional, Rivet, Jean-Pierre, additional, Vernet, David, additional, Devogèle, Maxime, additional, Shappee, Benjamin, additional, Holoien, Thomas, additional, Heras, Teófilo Arranz, additional, Bonnardeau, Michel, additional, Cook, Michael, additional, Coulter, Daniel, additional, Debackère, André, additional, Dvorak, Shawn, additional, Foster, James R., additional, Goff, William, additional, Hambsch, Franz-Josef, additional, Harris, Barbara, additional, Myers, Gordon, additional, Nelson, Peter, additional, Popov, Velimir, additional, Solomon, Rob, additional, Stein, William L., additional, Stone, Geoff, additional, and Vietje, Brad, additional

Published
2016
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30. RZ Leonis Minoris bridging between ER Ursae Majoris-type dwarf nova and nova-like system

Author

Kato, Taichi, Ishioka, Ryoko, Isogai, Keisuke, Kimura, Mariko, Imada, Akira, Miller, Ian, Masumoto, Kazunari, Nishino, Hirochika, Kojiguchi, Naoto, Kawabata, Miho, Sakai, Daisuke, Sugiura, Yuki, Furukawa, Hisami, Yamamura, Kenta, Kobayashi, Hiroshi, Matsumoto, Katsura, Wang, Shiang-Yu, Chou, Yi, Ngeow, Chow-Choong, Chen, Wen-Ping, Panwar, Neelam, Lin, Chi-Sheng, Hsiao, Hsiang-Yao, Guo, Jhen-Kuei, Lin, Chien-Cheng, Omarov, Chingis, Kusakin, Anatoly, Krugov, Maxim, Starkey, Donn R., Pavlenko, Elena P., Antonyuk, Kirill A., Sosnjvskij, Aleksei A., Antonyuk, Oksana I., Pit, Nikolai V., Baklanov, Alex V., Babina, Julia V., Itoh, Hiroshi, Padovan, Stefano, Akazawa, Hidehiko, Kafka, Stella, de Miguel, Enrique, Pickard, Roger D., Kiyota, Seiichiro, Shugarov, Sergey Yu., Chochol, Drahomir, Krushevska, Viktoriia, Sekeráš, Matej, Pikalova, Olga, Sabo, Richard, Dubovsky, Pavol A., Kudzej, Igor, Ulowetz, Joseph, Dvorak, Shawn, Stone, Geoff, Tordai, Tamás, Dubois, Franky, Logie, Ludwig, Rau, Steve, Vanaverbeke, Siegfried, Vanmunster, Tonny, Oksanen, Arto, Maeda, Yutaka, Kasai, Kiyoshi, Katysheva, Natalia, Morelle, Etienne, Neustroev, Vitaly V., and Sjoberg, George

Abstract

We observed RZ LMi, which is renowned for its extremely short (∼19 d) supercycle and is a member of a small, unusual class of cataclysmic variables called ER UMa-type dwarf novae, in 2013 and 2016. In 2016, the supercycles of this object substantially lengthened in comparison to the previous measurements to 35, 32, and 60 d for three consecutive superoutbursts. We consider that the object virtually experienced a transition to the nova-like state (permanent superhumper). This observed behavior reproduced the prediction of the thermal-tidal instability model extremely well. We detected a precursor in the 2016 superoutburst and detected growing (stage A) superhumps with a mean period of 0.0602(1) d in 2016 and in 2013. Combined with the period of superhumps immediately after the superoutburst, the mass ratio is not as small as in WZ Sge-type dwarf novae, having orbital periods similar to RZ LMi. By using least absolute shrinkage and selection operator (Lasso) two-dimensional power spectra, we detected possible negative superhumps with a period of 0.05710(1) d. We estimated an orbital period of 0.05792 d, which suggests a mass ratio of 0.105(5). This relatively large mass ratio is even above that of ordinary SU UMa-type dwarf novae, and it is also possible that the exceptionally high mass-transfer rate in RZ LMi may be a result of a stripped secondary with an evolved core in a system evolving toward an AM CVn-type object.

Published
2024
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31. RZ Leonis Minoris bridging between ER Ursae Majoris-type dwarf nova and nova-like system

Author

Kato, Taichi, primary, Ishioka, Ryoko, additional, Isogai, Keisuke, additional, Kimura, Mariko, additional, Imada, Akira, additional, Miller, Ian, additional, Masumoto, Kazunari, additional, Nishino, Hirochika, additional, Kojiguchi, Naoto, additional, Kawabata, Miho, additional, Sakai, Daisuke, additional, Sugiura, Yuki, additional, Furukawa, Hisami, additional, Yamamura, Kenta, additional, Kobayashi, Hiroshi, additional, Matsumoto, Katsura, additional, Wang, Shiang-Yu, additional, Chou, Yi, additional, Ngeow, Chow-Choong, additional, Chen, Wen-Ping, additional, Panwar, Neelam, additional, Lin, Chi-Sheng, additional, Hsiao, Hsiang-Yao, additional, Guo, Jhen-Kuei, additional, Lin, Chien-Cheng, additional, Omarov, Chingis, additional, Kusakin, Anatoly, additional, Krugov, Maxim, additional, Starkey, Donn R., additional, Pavlenko, Elena P., additional, Antonyuk, Kirill A., additional, Sosnjvskij, Aleksei A., additional, Antonyuk, Oksana I., additional, Pit, Nikolai V., additional, Baklanov, Alex V., additional, Babina, Julia V., additional, Itoh, Hiroshi, additional, Padovan, Stefano, additional, Akazawa, Hidehiko, additional, Kafka, Stella, additional, de Miguel, Enrique, additional, Pickard, Roger D., additional, Kiyota, Seiichiro, additional, Shugarov, Sergey Yu., additional, Chochol, Drahomir, additional, Krushevska, Viktoriia, additional, Sekeráš, Matej, additional, Pikalova, Olga, additional, Sabo, Richard, additional, Dubovsky, Pavol A., additional, Kudzej, Igor, additional, Ulowetz, Joseph, additional, Dvorak, Shawn, additional, Stone, Geoff, additional, Tordai, Tamás, additional, Dubois, Franky, additional, Logie, Ludwig, additional, Rau, Steve, additional, Vanaverbeke, Siegfried, additional, Vanmunster, Tonny, additional, Oksanen, Arto, additional, Maeda, Yutaka, additional, Kasai, Kiyoshi, additional, Katysheva, Natalia, additional, Morelle, Etienne, additional, Neustroev, Vitaly V., additional, and Sjoberg, George, additional

Published
2016
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32. Survey of period variations of superhumps in SU UMa-type dwarf novae. VIII. The eighth year (2015–2016)

Author

Kato, Taichi, primary, Hambsch, Franz-Josef, additional, Monard, Berto, additional, Vanmunster, Tonny, additional, Maeda, Yutaka, additional, Miller, Ian, additional, Itoh, Hiroshi, additional, Kiyota, Seiichiro, additional, Isogai, Keisuke, additional, Kimura, Mariko, additional, Imada, Akira, additional, Tordai, Tamás, additional, Akazawa, Hidehiko, additional, Tanabe, Kenji, additional, Otani, Noritoshi, additional, Ogi, Minako, additional, Ando, Kazuko, additional, Takigawa, Naoki, additional, Dubovsky, Pavol A., additional, Kudzej, Igor, additional, Shugarov, Sergey Yu., additional, Katysheva, Natalia, additional, Golysheva, Polina, additional, Gladilina, Natalia, additional, Chochol, Drahomir, additional, Starr, Peter, additional, Kasai, Kiyoshi, additional, Pickard, Roger D., additional, Miguel, Enrique de, additional, Kojiguchi, Naoto, additional, Sugiura, Yuki, additional, Fukushima, Daiki, additional, Yamada, Eiji, additional, Uto, Yusuke, additional, Kamibetsunawa, Taku, additional, Tatsumi, Taiki, additional, Takeda, Nao, additional, Matsumoto, Katsura, additional, Cook, Lewis M., additional, Pavlenko, Elena P., additional, Babina, Julia V., additional, Pit, Nikolaj V., additional, Antonyuk, Oksana I., additional, Antonyuk, Kirill A., additional, Sosnovskij, Aleksei A., additional, Baklanov, Aleksei V., additional, Kafka, Stella, additional, Stein, William, additional, Voloshina, Irina B., additional, Ruiz, Javier, additional, Sabo, Richard, additional, Dvorak, Shawn, additional, Stone, Geoff, additional, Andreev, Maksim V., additional, Antipin, Sergey V., additional, Zubareva, Alexandra M., additional, Zaostrojnykh, Anna M., additional, Richmond, Michael, additional, Shears, Jeremy, additional, Dubois, Franky, additional, Logie, Ludwig, additional, Rau, Steve, additional, Vanaverbeke, Siegfried, additional, Simon, Andrei, additional, Oksanen, Arto, additional, Goff, William N., additional, Bolt, Greg, additional, Dębski, Bartłomiej, additional, Kochanek, Christopher S., additional, Shappee, Benjamin, additional, Stanek, Krzysztof Z., additional, Prieto, José L., additional, Stubbings, Rod, additional, Muyllaert, Eddy, additional, Hiraga, Mitsutaka, additional, Horie, Tsuneo, additional, Schmeer, Patrick, additional, and Hirosawa, Kenji, additional

Published
2016
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33. ASASSN-16dt and ASASSN-16hg: Promising candidate period bouncers.

Author

Mariko KIMURA, Keisuke ISOGAI, Taichi KATO, Kenta TAGUCHI, Yasuyuki WAKAMATSU, HAMBSCH, Franz-Josef, MONARD, Berto, MYERS, Gordon, DVORAK, Shawn, STARR, Peter, BRINCAT, Stephen M., DE MIGUEL, Enrique, ULOWETZ, Joseph, Hiroshi ITOH, STONE, Geoff, and Daisaku NOGAMI

Subjects
PHOTOMETRY, DWARF novae, CATACLYSMIC variable stars, LUMINOSITY, LIGHT curves
Abstract

We present optical photometry of superoutbursts that occurred in 2016 of two WZ Sge-type dwarf novae (DNe), ASASSN-16dt and ASASSN-16hg. Their light curves showed a dip in brightness between the first plateau stage with no ordinary superhumps (or early superhumps) and the second plateau stage with ordinary superhumps. We find that the dip is produced by the slow evolution of the 3 : 1 resonance tidal instability and that it would likely be observed in low mass-ratio objects. An estimated mass ratio (q ≡ M2/M1) from the period of developing (stage A) superhumps [0.06420(3) d] was 0.036(2) in ASASSN-16dt. Additionally, its superoutburst has many properties similar to those in other low-q WZ Sge-type DNe: long-lasting stage-A superhumps, small superhump amplitudes, long delay of ordinary-superhump appearances, and a slow decline rate in the plateau stage with superhumps. Its very small mass ratio and observational characteristics suggest that this system is one of the best candidates for a period bouncer--a binary accounting for the missing population of post-period minimum cataclysmic variables. Although it is not clearly verified due to the lack of detection of stage-A superhumps, ASASSN-16hg might be a possible candidate for period bouncers on the basis of the morphology of its light curves and the small superhump amplitudes. Many outburst properties of period bouncer candidates would originate from the small tidal effects of their secondary stars. [ABSTRACT FROM AUTHOR]

Published
2018
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34. ASASSN-16eg: New candidate for a long-period WZ Sge-type dwarf nova.

Author

Yasuyuki WAKAMATSU, Keisuke ISOGAI, Mariko KIMURA, Taichi KATO, VANMUNSTER, Tonny, STONE, Geoff, TORDAI, Tamás, Michael RICHMOND, MILLER, Ian, Arto OKSANEN, Hiroshi ITOH, Hidehiko AKAZAWA, Seiichiro KIYOTA, DE MIGUEL, Enrique, PAVLENKO, Elena P., ANTONYUK, Kirill A., ANTONYUK, Oksana I., NEUSTROEV, Vitaly V., George SJOBERG, and DUBOVSKY, Pavol A.

Subjects
DWARF novae, RESONANCE, MASS transfer, PHOTOMETRY, PLATEAUS
Abstract

We report on our photometric observations of the 2016 superoutburst of ASASSN-16eg. This object showed aWZ Sge-type superoutburst with prominent early superhumps with a period of 0.075478(8) d and a post-superoutburst rebrightening. During the superoutburst plateau, it showed ordinary superhumps with a period of 0.077880(3) d and a period derivative of 10.6(1.1) × 10-5 in stage B. The orbital period (Porb), which is almost identical with the period of the early superhumps, is exceptionally long for a WZ Sge-type dwarf nova. The mass ratio (q = M2/M1) estimated from the period of developing (stage A) superhumps is 0.166(2), which is also too large for a WZ Sge-type dwarf nova. This suggests that the 2 : 1 resonance can be reached in such high-q systems, contrary to our expectation. Such conditions are considered to be achieved if the mass-transfer rate is much lower than those in typical SU UMa-type dwarf novae that have comparable orbital periods to ASASSN-16eg, and a resultant accumulation of a large amount of matter on the disk is realized at the onset of an outburst. We examined other candidates for longperiod WZ Sge-type dwarf novae for their supercycles, which are considered to reflect the mass-transfer rate, and found that V1251 Cyg and RZ Leo have longer supercycles than those of other WZ Sge-type dwarf novae. This result indicates that these long-period objects including ASASSN-16eg have a low mass-transfer rate in comparison to other WZ Sge-type dwarf novae. [ABSTRACT FROM AUTHOR]

Published
2017
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35. OT J002656.6+284933 (CSS101212:002657+ 284933): an SUUMa-type dwarf nova with the longest superhump period.

Author

Taichi KATO, TORDAI, Tamás, LITTLEFIELD, Colin, Kiyoshi KASAI, SHUGAROV, Sergey Yu., KATYSHEVA, Natalia, ZAOSTROJNYKH, Anna M., PICKARD, Roger D., DE MIGUEL, Enrique, ANTONYUK, Kirill, ANTONYUK, Oksana, PAVLENKO, Elena P., PIT, Nikolai, Hiroshi ITOH, RUIZ, Javier, ISOGAI, Keisuke, Mariko KIMURA, Yasuyuki WAKAMATSU, VANMUNSTER, Tonny, and STONE, Geoff

Subjects
DWARF novae, METEOR showers, GALAXIES
Abstract

We observed the 2016 outburst of OT J002656.6+284933 (CSS101212:002657+284933) and found that it has the longest recorded [0.13225(1) d on average] superhumps among SUUMa-type dwarf novae. The object is the third known SUUMa-type dwarf nova above the period gap. The outburst, however, was unlike ordinary long-period SUUMa-type dwarf novae in that it showed two post-outburst rebrightenings. It showed superhump evolution similar to short-period SUUMa-type dwarf novae. We could constrain themass ratio to less than 0.15 (most likely between 0.10 and 0.15) by using superhump periods in the early and post-superoutburst stages. These results suggest the possibility that OT J002656.6+284933 has an anomalously undermassive secondary and it should have followed a different evolutionary track from the standard one. [ABSTRACT FROM AUTHOR]

Published
2017
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36. Safe and efficient sheet metal procedures

Author

Callis, Frank and Stone, Geoff

Subjects
Degassing of metals, Metals, Technology application, Business, Construction and materials industries
Abstract

Companies naturally seek efficiency in business operations as a matter of staying profitable and surviving. Efficiency is generally achieved by the automation of processes with machinery and equipment. It is [...]

Published
2005

40. Bar none

Author

Stone, Geoff

Abstract

"BAR EXAM" WAS A GREAT little piece (September 2003). I've often found myself in line at Whole Foods looking at the nutrition information on various energy bars. It always struck […]

Published
2003

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