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1. A survey for variable stars with small telescopes: IX -- Evolution of Spot Properties on YSOs in IC5070

Author

Herbert, Carys, Froebrich, Dirk, Vanaverbeke, Siegfried, Scholz, Aleks, Eislöffel, Jochen, Urtly, Thomas, Walton, Ivan L., Wiersema, Klaas, Quinn, Nick J., Piehler, Georg, Aimar, Mario Morales, García, Rafael Castillo, Vanmunster, Tonny, Alfaro, Francisco C. Soldán, de la Cuesta, Faustino García, Licchelli, Domenico, Perez, Alex Escartin, Mañanes, Esteban Fernández, Ribes, Noelia Graciá, González, José Luis Salto, Futcher, Stephen R. L., Nelson, Tim, Dvorak, Shawn, Moździerski, Dawid, Kotysz, Krzysztof, Mikołajczyk, Przemysław, Fleming, George, Phillips, Mark, Vale, Tony, Dubois, Franky, Eggenstein, Heinz-Bernd, Heald, Michael A., Lewin, Pablo, OKeeffe, Derek, Popowicz, Adam, Bernacki, Krzysztof, Malcher, Andrzej, Lasota, Slawomir, Fiolka, Jerzy, Dustor, Adam, Percy, Stephen C., Devine, Pat, Patel, Aashini L., Dickers, Matthew D., Dover, Lord, Grozdanova, Ivana I., Urquhart, James S., and Lynch, Chris J. R.

Subjects
Astrophysics - Solar and Stellar Astrophysics, Astrophysics - Astrophysics of Galaxies
Abstract

We present spot properties on 32 periodic young stellar objects in IC 5070. Long term, $\sim$5 yr, light curves in the $V$, $R$, and $I$-bands are obtained through the HOYS (Hunting Outbursting Young Stars) citizen science project. These are dissected into six months long slices, with 3 months oversampling, to measure 234 sets of amplitudes in all filters. We fit 180 of these with reliable spot solutions. Two thirds of spot solutions are cold spots, the lowest is 2150 K below the stellar temperature. One third are warm spots that are above the stellar temperature by less than $\sim$2000 K. Cold and warm spots have maximum surface coverage values of 40 percent, although only 16 percent of warm spots are above 20 percent surface coverage as opposed to 60 percent of the cold spots. Warm spots are most likely caused by a combination of plages and low density accretion columns, most common on objects without inner disc excess emission in $K-W2$. Five small hot spot solutions have $<3$ percent coverage and are 3000 - 5000 K above the stellar temperature. These are attributed to accretion, and four of them occur on the same object. The majority of our objects are likely to be accreting. However, we observe very few accretion hot spots as either the accretion is not stable on our timescale or the photometry is dominated by other features. We do not identify cyclical spot behaviour on the targets. We additionally identify and discuss a number of objects that have interesting amplitudes, phase changes, or spot properties., Comment: Accepted for publication by MNRAS. 17 + 7 pages, 7 + 23 figures, 1 table

Published
2024

2. A survey for variable young stars with small telescopes: VI -- Analysis of the outbursting Be stars NSW284, Gaia19eyy, and VES263

Author

Froebrich, Dirk, Hillenbrand, Lynne A., Herbert, Carys, De, Kishalay, Eislöffel, Jochen, Campbell-White, Justyn, Kahar, Ruhee, Hambsch, Franz-Josef, Urtly, Thomas, Popowicz, Adam, Bernacki, Krzysztof, Malcher, Andrzej, Lasota, Slawomir, Fiolka, Jerzy, Jozwik-Wabik, Piotr, Dubois, Franky, Logie, Ludwig, Rau, Steve, Phillips, Mark, Fleming, George, Farfán, Rafael Gonzalez, Alfaro, Francisco C. Soldán, Nelson, Tim, Futcher, Stephen R. L., Rolfe, Samantha M., Campbell, David A., Vale, Tony, Devine, Pat, Moździerski, Dawid, Mikołajczyk, Przemysław J., Eggenstein, Heinz-Bernd, Rodriguez, Diego, Walton, Ivan L, Vanaverbeke, Siegfried, Merrikin, Barry, Öğmen, Yenal, Perez, Alex Escartin, Aimar, Mario Morales, Piehler, Georg, Dover, Lord, Patel, Aashini L., Miller, Niall, Finch, Jack, Hankins, Matt, Moore, Anna M., Travouillon, Tony, and Szczepanski, Marek

Subjects
Astrophysics - Solar and Stellar Astrophysics
Abstract

This paper is one in a series reporting results from small telescope observations of variable young stars. Here, we study the repeating outbursts of three likely Be stars based on long-term optical, near-infrared, and mid-infrared photometry for all three objects, along with follow-up spectra for two of the three. The sources are characterised as rare, truly regularly outbursting Be stars. We interpret the photometric data within a framework for modelling light curve morphology, and find that the models correctly predict the burst shapes, including their larger amplitudes and later peaks towards longer wavelengths. We are thus able to infer the start and end times of mass loading into the circumstellar disks of these stars. The disk sizes are typically 3-6 times the areas of the central star. The disk temperatures are ~40%, and the disk luminosities are ~10% of those of the central Be star, respectively. The available spectroscopy is consistent with inside-out evolution of the disk. Higher excitation lines have larger velocity widths in their double-horned shaped emission profiles. Our observations and analysis support the decretion disk model for outbursting Be stars., Comment: Accepted for publication by MNRAS. 20 pages, 11 figures, 2 tables

Published
2023
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3. A survey for variable young stars with small telescopes: IV -- Rotation Periods of YSOs in IC5070

Author

Froebrich, Dirk, Derezea, Efthymia, Scholz, Aleks, Eislöffel, Jochen, Vanaverbeke, Siegfried, Kume, Alfred, Herbert, Carys, Campbell-White, Justyn, Miller, Niall, Stecklum, Bringfried, Makin, Sally V., Urtly, Thomas, Alfaro, Francisco C. Soldán, Schwendeman, Erik, Stone, Geoffrey, Phillips, Mark, Fleming, George, Farfán, Rafael Gonzalez, Vanmunster, Tonny, Heald, Michael A., Mañanes, Esteban Fernández, Nelson, Tim, Eggenstein, Heinz-Bernd, Dubois, Franky, Logie, Ludwig, Rau, Steve, Wiersema, Klaas, Quinn, Nick, Rodriguez, Diego, García, Rafael Castillo, Killestein, Thomas, Vale, Tony, Licchelli, Domenico, Deldem, Marc, Piehler, Georg, Moździerski, Dawid, Kotysz, Krzysztof, Kowalska, Katarzyna, Mikołajczyk, Przemysław, Futcher, Stephen R. L., Long, Timothy P., Aimar, Mario Morales, Merrikin, Barry, Johnstone, Stephen, Dubovský, Pavol A., Kudzej, Igor, Pickard, Roger, Billington, Samuel J., Dover, Lord, Zegmott, Tarik, Evitts, Jack J., Munia, Alejandra Traspas, and Price, Mark C.

Subjects
Astrophysics - Solar and Stellar Astrophysics, Astrophysics - Astrophysics of Galaxies
Abstract

Studying rotational variability of young stars is enabling us to investigate a multitude of properties of young star-disk systems. We utilise high cadence, multi-wavelength optical time series data from the Hunting Outbursting Young Stars citizen science project to identify periodic variables in the Pelican Nebula (IC5070). A double blind study using nine different period-finding algorithms was conducted and a sample of 59 periodic variables was identified. We find that a combination of four period finding algorithms can achieve a completeness of 85% and a contamination of 30% in identifying periods in inhomogeneous data sets. The best performing methods are periodograms that rely on fitting a sine curve. Utilising GaiaEDR3 data, we have identified an unbiased sample of 40 periodic YSOs, without using any colour or magnitude selections. With a 98.9% probability we can exclude a homogeneous YSO period distribution. Instead we find a bi-modal distribution with peaks at three and eight days. The sample has a disk fraction of 50%, and its statistical properties are in agreement with other similarly aged YSOs populations. In particular, we confirm that the presence of the disk is linked to predominantly slow rotation and find a probability of 4.8$\times$10$^{-3}$ that the observed relation between period and presence of a disk has occurred by chance. In our sample of periodic variables, we also find pulsating giants, an eclipsing binary, and potential YSOs in the foreground of IC5070., Comment: 25 pages, 14 figures, 5 tables, accepted for publication in MNRAS

Published
2021
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4. A survey for variable young stars with small telescopes: II -- Mapping a protoplanetary disk with stable structures at 0.15 AU

Author

Evitts, Jack J., Froebrich, Dirk, Scholz, Aleks, Eislöffel, Jochen, Campbell-White, Justyn, Furnell, Will, Urtly, Thomas, Pickard, Roger, Wiersema, Klaas, Dubovský, Pavol A., Kudzej, Igor, Naves, Ramon, Aimar, Mario Morales, García, Rafael Castillo, Vanmunster, Tonny, Schwendeman, Erik, Alfaro, Francisco C. Soldán, Johnstone, Stephen, Farfán, Rafael Gonzalez, Killestein, Thomas, Casal, Jesús Delgado, de la Cuesta, Faustino García, Roberts, Dean, Kolb, Ulrich, Montoro, Luís, Licchelli, Domenico, Perez, Alex Escartin, Perez, Carlos Perelló, Deldem, Marc, Futcher, Stephen R. L., Nelson, Tim, Dvorak, Shawn, Moździerski, Dawid, Quinn, Nick, Kotysz, Krzysztof, Kowalska, Katarzyna, Mikołajczyk, Przemysław, Fleming, George, Phillips, Mark, Vale, Tony, Dubois, Franky, Logie, Ludwig, Rau, Steve, Vanaverbeke, Siegfried, Merrikin, Barry, Mañanes, Esteban Fernández, Erdelyi, Emery, Carballo, Juan-Luis Gonzalez, Martinez, Fernando Limon, Long, Timothy P., Delgado, Adolfo San Segundo, González, Josép Luis Salto, Espasa, Luis Tremosa, Piehler, Georg, Crumpton, James, Dover, Lord, Billington, Samuel J., DArcy, Emma, Makin, Sally V., and Stecklum, Bringfried

Subjects
Astrophysics - Astrophysics of Galaxies, Astrophysics - Solar and Stellar Astrophysics
Abstract

The HOYS citizen science project conducts long term, multifilter, high cadence monitoring of large YSO samples with a wide variety of professional and amateur telescopes. We present the analysis of the light curve of V1490Cyg in the Pelican Nebula. We show that colour terms in the diverse photometric data can be calibrated out to achieve a median photometric accuracy of 0.02mag in broadband filters, allowing detailed investigations into a variety of variability amplitudes over timescales from hours to several years. Using GaiaDR2 we estimate the distance to the Pelican Nebula to be 870$^{+70}_{-55}$pc. V1490Cyg is a quasi-periodic dipper with a period of 31.447$\pm$0.011d. The obscuring dust has homogeneous properties, and grains larger than those typical in the ISM. Larger variability on short timescales is observed in U and R$_c-$H$\alpha$, with U-amplitudes reaching 3mag on timescales of hours, indicating the source is accreting. The H$\alpha$ equivalent width and NIR/MIR colours place V1490Cyg between CTTS/WTTS and transition disk objects. The material responsible for the dipping is located in a warped inner disk, about 0.15AU from the star. This mass reservoir can be filled and emptied on time scales shorter than the period at a rate of up to 10$^{-10}$M$_\odot$/yr, consistent with low levels of accretion in other T Tauri stars. Most likely the warp at this separation from the star is induced by a protoplanet in the inner accretion disk. However, we cannot fully rule out the possibility of an AA Tau-like warp, or occultations by the Hill sphere around a forming planet., Comment: 27 pages, 17 figures, accepted by MNRAS, full version with full appendix available at http://astro.kent.ac.uk/~df/

Published
2020
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5. A survey for variable young stars with small telescopes – IX. Evolution of spot properties on YSOs in IC 5070

Author

Herbert, Carys, primary, Froebrich, Dirk, additional, Vanaverbeke, Siegfried, additional, Scholz, Aleks, additional, Eislöffel, Jochen, additional, Urtly, Thomas, additional, Walton, Ivan L, additional, Wiersema, Klaas, additional, Quinn, Nick J, additional, Piehler, Georg, additional, Aimar, Mario Morales, additional, García, Rafael Castillo, additional, Vanmunster, Tonny, additional, Alfaro, Francisco C Soldán, additional, de la Cuesta, Faustino García, additional, Licchelli, Domenico, additional, Perez, Alex Escartin, additional, Mañanes, Esteban Fernández, additional, Ribes, Noelia Graciá, additional, González, José Luis Salto, additional, Futcher, Stephen R L, additional, Nelson, Tim, additional, Dvorak, Shawn, additional, Moździerski, Dawid, additional, Kotysz, Krzysztof, additional, Mikołajczyk, Przemysław, additional, Fleming, George, additional, Phillips, Mark, additional, Vale, Tony, additional, Dubois, Franky, additional, Eggenstein, Heinz-Bernd, additional, Heald, Michael A, additional, Lewin, Pablo, additional, OKeeffe, Derek, additional, Popowicz, Adam, additional, Bernacki, Krzysztof, additional, Malcher, Andrzej, additional, Lasota, Slawomir, additional, Fiolka, Jerzy, additional, Dustor, Adam, additional, Percy, Stephen C, additional, Devine, Pat, additional, Patel, Aashini L, additional, Dickers, Matthew D, additional, Dover, Lord, additional, Grozdanova, Ivana I, additional, Urquhart, James S, additional, and Lynch, Chris J R, additional

Published
2024
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6. A survey for variable young stars with small telescopes: IX - Evolution of spot properties on YSOs in IC 5070

Author

Herbert, Carys, Froebrich, Dirk, Vanaverbeke, Siegfried, Scholz, Aleks, Eislöffel, Jochen, Urtly, Thomas, Walton, Ivan L, Wiersema, Klaas, Quinn, Nick J, Piehler, Georg, Aimar, Mario Morales, García, Rafael Castillo, Vanmunster, Tonny, Alfaro, Francisco C Soldán, de la Cuesta, Faustino García, Licchelli, Domenico, Perez, Alex Escartin, Mañanes, Esteban Fernández, Ribes, Noelia Graciá, González, José Luis Salto, Futcher, Stephen R L, Nelson, Tim, Dvorak, Shawn, Moździerski, Dawid, Kotysz, Krzysztof, Mikołajczyk, Przemysław, Fleming, George, Phillips, Mark, Vale, Tony, Dubois, Franky, Eggenstein, Heinz-Bernd, Heald, Michael A, Lewin, Pablo, OKeeffe, Derek, Popowicz, Adam, Bernacki, Krzysztof, Malcher, Andrzej, Lasota, Slawomir, Fiolka, Jerzy, Dustor, Adam, Percy, Stephen C, Devine, Pat, Patel, Aashini L, Dickers, Matthew D., Dover, Lord, Grozdanova, Ivana I., Urquhart, James S., Lynch, Chris J.R., Herbert, Carys, Froebrich, Dirk, Vanaverbeke, Siegfried, Scholz, Aleks, Eislöffel, Jochen, Urtly, Thomas, Walton, Ivan L, Wiersema, Klaas, Quinn, Nick J, Piehler, Georg, Aimar, Mario Morales, García, Rafael Castillo, Vanmunster, Tonny, Alfaro, Francisco C Soldán, de la Cuesta, Faustino García, Licchelli, Domenico, Perez, Alex Escartin, Mañanes, Esteban Fernández, Ribes, Noelia Graciá, González, José Luis Salto, Futcher, Stephen R L, Nelson, Tim, Dvorak, Shawn, Moździerski, Dawid, Kotysz, Krzysztof, Mikołajczyk, Przemysław, Fleming, George, Phillips, Mark, Vale, Tony, Dubois, Franky, Eggenstein, Heinz-Bernd, Heald, Michael A, Lewin, Pablo, OKeeffe, Derek, Popowicz, Adam, Bernacki, Krzysztof, Malcher, Andrzej, Lasota, Slawomir, Fiolka, Jerzy, Dustor, Adam, Percy, Stephen C, Devine, Pat, Patel, Aashini L, Dickers, Matthew D., Dover, Lord, Grozdanova, Ivana I., Urquhart, James S., and Lynch, Chris J.R.

Abstract

We present spot properties on 32 periodic young stellar objects in IC 5070. Long term, ∼5 yr, light curves in the V, R, and I-bands are obtained through the HOYS (Hunting Outbursting Young Stars) citizen science project. These are dissected into six months long slices, with 3 months oversampling, to measure 234 sets of amplitudes in all filters. We fit 180 of these with reliable spot solutions. Two thirds of spot solutions are cold spots, the lowest is 2150 K below the stellar temperature. One third are warm spots that are above the stellar temperature by less than ∼2000 K. Cold and warm spots have maximum surface coverage values of 40 per cent, although only 16 per cent of warm spots are above 20 per cent surface coverage as opposed to 60 per cent of the cold spots. Warm spots are most likely caused by a combination of plages and low density accretion columns, most common on objects without inner disc excess emission in K − W2. Five small hot spot solutions have <3 percent coverage and are 3000 – 5000 K above the stellar temperature. These are attributed to accretion, and four of them occur on the same object. The majority of our objects are likely to be accreting. However, we observe very few accretion hot spots as either the accretion is not stable on our timescale or the photometry is dominated by other features. We do not identify cyclical spot behaviour on the targets. We additionally identify and discuss a number of objects that have interesting amplitudes, phase changes, or spot properties.

Published
2024

7. A survey for variable young stars with small telescopes: VI – Analysis of the outbursting Be stars NSW 284, gaia 19eyy, and VES 263

Author

Froebrich, Dirk, primary, Hillenbrand, Lynne A, additional, Herbert, Carys, additional, De, Kishalay, additional, Eislöffel, Jochen, additional, Campbell-White, Justyn, additional, Kahar, Ruhee, additional, Hambsch, Franz-Josef, additional, Urtly, Thomas, additional, Popowicz, Adam, additional, Bernacki, Krzysztof, additional, Malcher, Andrzej, additional, Lasota, Slawomir, additional, Fiolka, Jerzy, additional, Jozwik-Wabik, Piotr, additional, Dubois, Franky, additional, Logie, Ludwig, additional, Rau, Steve, additional, Phillips, Mark, additional, Fleming, George, additional, Farfán, Rafael Gonzalez, additional, Alfaro, Francisco C Soldán, additional, Nelson, Tim, additional, Futcher, Stephen R L, additional, Rolfe, Samantha M, additional, Campbell, David A, additional, Vale, Tony, additional, Devine, Pat, additional, Moździerski, Dawid, additional, Mikołajczyk, Przemysław J, additional, Eggenstein, Heinz-Bernd, additional, Rodriguez, Diego, additional, Walton, Ivan L, additional, Vanaverbeke, Siegfried, additional, Merrikin, Barry, additional, Öğmen, Yenal, additional, Perez, Alex Escartin, additional, Aimar, Mario Morales, additional, Piehler, Georg, additional, Dover, Lord, additional, Patel, Aashini L, additional, Miller, Niall, additional, Finch, Jack, additional, Hankins, Matt, additional, Moore, Anna M, additional, Travouillon, Tony, additional, and Szczepanski, Marek, additional

Published
2023
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8. A survey for variable young stars with small telescopes – IV. Rotation periods of YSOs in IC 5070

Author

Froebrich, Dirk, primary, Derezea, Efthymia, additional, Scholz, Aleks, additional, Eislöffel, Jochen, additional, Vanaverbeke, Siegfried, additional, Kume, Alfred, additional, Herbert, Carys, additional, Campbell-White, Justyn, additional, Miller, Niall, additional, Stecklum, Bringfried, additional, Makin, Sally V, additional, Urtly, Thomas, additional, Soldán Alfaro, Francisco C, additional, Schwendeman, Erik, additional, Stone, Geoffrey, additional, Phillips, Mark, additional, Fleming, George, additional, Gonzalez Farfán, Rafael, additional, Vanmunster, Tonny, additional, Heald, Michael A, additional, Fernández Mañanes, Esteban, additional, Nelson, Tim, additional, Eggenstein, Heinz-Bernd, additional, Dubois, Franky, additional, Logie, Ludwig, additional, Rau, Steve, additional, Wiersema, Klaas, additional, Quinn, Nick, additional, Rodriguez, Diego, additional, Castillo García, Rafael, additional, Killestein, Thomas, additional, Vale, Tony, additional, Licchelli, Domenico, additional, Deldem, Marc, additional, Piehler, Georg, additional, Moździerski, Dawid, additional, Kotysz, Krzysztof, additional, Kowalska, Katarzyna, additional, Mikołajczyk, Przemysław, additional, Futcher, Stephen R L, additional, Long, Timothy P, additional, Morales Aimar, Mario, additional, Merrikin, Barry, additional, Johnstone, Stephen, additional, Dubovský, Pavol A, additional, Kudzej, Igor, additional, Pickard, Roger, additional, Billington, Samuel J, additional, Dover, Lord, additional, Zegmott, Tarik, additional, Evitts, Jack J, additional, Traspas Munia, Alejandra, additional, and Price, Mark C, additional

Published
2021
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9. A survey for variable young stars with small telescopes - IV. Rotation periods of YSOs in IC 5070

Author

Froebrich, Dirk, Derezea, Efthymia, Scholz, Aleks, Eislöffel, Jochen, Vanaverbeke, Siegfried, Kume, Alfred, Herbert, Carys, Campbell-White, Justyn, Miller, Niall, Stecklum, Bringfried, Makin, Sally V., Urtly, Thomas, Soldán Alfaro, Francisco C., Schwendeman, Erik, Stone, Geoffrey, Phillips, Mark, Fleming, George, Gonzalez Farfán, Rafael, Vanmunster, Tonny, Heald, Michael A., Fernández Mañanes, Esteban, Nelson, Tim, Eggenstein, Heinz-Bernd, Dubois, Franky, Logie, Ludwig, Rau, Steve, Wiersema, Klaas, Quinn, Nick, Rodriguez, Diego, Castillo Garc\'\ia, Rafael, Killestein, Thomas, Vale, Tony, Licchelli, Domenico, Deldem, Marc, Piehler, Georg, Moździerski, Dawid, Kotysz, Krzysztof, Kowalska, Katarzyna, Mikołajczyk, Przemysław, Futcher, Stephen R.L., Long, Timothy P., Morales Aimar, Mario, Merrikin, Barry, Johnstone, Stephen, Dubovský, Pavol A., Kudzej, Igor, Pickard, Roger, Billington, Samuel J., Dover, Lord, Zegmott, Tarik Joseph, Evitts, Jack J, Traspas Munia, Alejandra, Price, Mark C., Froebrich, Dirk, Derezea, Efthymia, Scholz, Aleks, Eislöffel, Jochen, Vanaverbeke, Siegfried, Kume, Alfred, Herbert, Carys, Campbell-White, Justyn, Miller, Niall, Stecklum, Bringfried, Makin, Sally V., Urtly, Thomas, Soldán Alfaro, Francisco C., Schwendeman, Erik, Stone, Geoffrey, Phillips, Mark, Fleming, George, Gonzalez Farfán, Rafael, Vanmunster, Tonny, Heald, Michael A., Fernández Mañanes, Esteban, Nelson, Tim, Eggenstein, Heinz-Bernd, Dubois, Franky, Logie, Ludwig, Rau, Steve, Wiersema, Klaas, Quinn, Nick, Rodriguez, Diego, Castillo Garc\'\ia, Rafael, Killestein, Thomas, Vale, Tony, Licchelli, Domenico, Deldem, Marc, Piehler, Georg, Moździerski, Dawid, Kotysz, Krzysztof, Kowalska, Katarzyna, Mikołajczyk, Przemysław, Futcher, Stephen R.L., Long, Timothy P., Morales Aimar, Mario, Merrikin, Barry, Johnstone, Stephen, Dubovský, Pavol A., Kudzej, Igor, Pickard, Roger, Billington, Samuel J., Dover, Lord, Zegmott, Tarik Joseph, Evitts, Jack J, Traspas Munia, Alejandra, and Price, Mark C.

Abstract

Studying rotational variability of young stars is enabling us to investigate a multitude of properties of young star-disc systems. We utilize high cadence, multiwavelength optical time series data from the Hunting Outbursting Young Stars citizen science project to identify periodic variables in the Pelican Nebula (IC 5070). A double blind study using nine different period-finding algorithms was conducted and a sample of 59 periodic variables was identified. We find that a combination of four period finding algorithms can achieve a completeness of 85 per cent and a contamination of 30 per cent in identifying periods in inhomogeneous data sets. The best performing methods are periodograms that rely on fitting a sine curve. Utilizing Gaia EDR3 data, we have identified an unbiased sample of 40 periodic young stellar objects (YSOs), without using any colour or magnitude selections. With a 98.9 per cent probability, we can exclude a homogeneous YSO period distribution. Instead, we find a bi-modal distribution with peaks at 3 and 8 d. The sample has a disc fraction of 50 per cent, and its statistical properties are in agreement with other similarly aged YSOs populations. In particular, we confirm that the presence of the disc is linked to predominantly slow rotation and find a probability of 4.8 × 10−3 that the observed relation between period and presence of a disc has occurred by chance. In our sample of periodic variables, we also find pulsating giants, an eclipsing binary, and potential YSOs in the foreground of IC 5070.

Published
2021

10. A survey for variable young stars with small telescopes: II – mapping a protoplanetary disc with stable structures at 0.15 au

Author

Evitts, Jack J, primary, Froebrich, Dirk, additional, Scholz, Aleks, additional, Eislöffel, Jochen, additional, Campbell-White, Justyn, additional, Furnell, Will, additional, Stecklum, Bringfried, additional, Urtly, Thomas, additional, Pickard, Roger, additional, Wiersema, Klaas, additional, Dubovský, Pavol A, additional, Kudzej, Igor, additional, Naves, Ramon, additional, Morales Aimar, Mario, additional, Castillo García, Rafael, additional, Vanmunster, Tonny, additional, Schwendeman, Erik, additional, Soldán Alfaro, Francisco C, additional, Johnstone, Stephen, additional, Gonzalez Farfán, Rafael, additional, Killestein, Thomas, additional, DelgadoCasal, Jesús, additional, García de la Cuesta, Faustino, additional, Roberts, Dean, additional, Kolb, Ulrich, additional, Montoro, Luís, additional, Licchelli, Domenico, additional, Escartin Perez, Alex, additional, Perelló Perez, Carlos, additional, Deldem, Marc, additional, Futcher, Stephen R L, additional, Nelson, Tim, additional, Dvorak, Shawn, additional, Moździerski, Dawid, additional, Quinn, Nick, additional, Kotysz, Krzysztof, additional, Kowalska, Katarzyna, additional, Mikołajczyk, Przemysław, additional, Fleming, George, additional, Phillips, Mark, additional, Vale, Tony, additional, Dubois, Franky, additional, Logie, Ludwig, additional, Rau, Steve, additional, Vanaverbeke, Siegfried, additional, Merrikin, Barry, additional, Fernández Mañanes, Esteban, additional, Erdelyi, Emery, additional, Gonzalez Carballo, Juan-Luis, additional, Limon Martinez, Fernando, additional, Long, Timothy P, additional, San Segundo Delgado, Adolfo, additional, Salto González, Josép Luis, additional, Tremosa Espasa, Luis, additional, Piehler, Georg, additional, Crumpton, James, additional, Billington, Samuel J, additional, D’Arcy, Emma, additional, Makin, Sally V, additional, and Dover, Lord, additional

Published
2020
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11. A survey for variable young stars with small telescopes: II - Mapping a protoplanetary disk with stable structures at 0.15 AU

Author

Evitts, Jack J., Froebrich, Dirk, Scholz, Aleks, Eislöffel, Jochen, Campbell-White, Justyn, Furnell, Will, Urtly, Thomas, Pickard, Roger, Wiersema, Klaas, Dubovský, Pavol A., Kudzej, Igor, Naves, Ramon, Aimar, Mario Morales, García, Rafael Castillo, Vanmunster, Tonny, Schwendeman, Erik, Alfaro, Francisco C. Soldán, Johnstone, Stephen, Farfán, Rafael Gonzalez, Killestein, Thomas, Casal, Jesús Delgado, de la Cuesta, Faustino García, Roberts, Dean, Kolb, Ulrich, Montoro, Luís, Licchelli, Domenico, Perez, Alex Escartin, Perez, Carlos Perelló, Deldem, Marc, Futcher, Stephen R. L., Nelson, Tim, Dvorak, Shawn, Moździerski, Dawid, Quinn, Nick, Kotysz, Krzysztof, Kowalska, Katarzyna, Mikołajczyk, Przemysław, Fleming, George, Phillips, Mark, Vale, Tony, Dubois, Franky, Logie, Ludwig, Rau, Steve, Vanaverbeke, Siegfried, Merrikin, Barry, Mañanes, Esteban Fernández, Erdelyi, Emery, Carballo, Juan-Luis Gonzalez, Martinez, Fernando Limon, Long, Timothy P., Segundo Delgado, Adolfo San, Salto González, Josép Luis, Espasa, Luis Tremosa, Piehler, Georg, Crumpton, James, Billington, Samuel J., D’Arcy, Emma, Makin, Sally V., Dover, Lord, Evitts, Jack J., Froebrich, Dirk, Scholz, Aleks, Eislöffel, Jochen, Campbell-White, Justyn, Furnell, Will, Urtly, Thomas, Pickard, Roger, Wiersema, Klaas, Dubovský, Pavol A., Kudzej, Igor, Naves, Ramon, Aimar, Mario Morales, García, Rafael Castillo, Vanmunster, Tonny, Schwendeman, Erik, Alfaro, Francisco C. Soldán, Johnstone, Stephen, Farfán, Rafael Gonzalez, Killestein, Thomas, Casal, Jesús Delgado, de la Cuesta, Faustino García, Roberts, Dean, Kolb, Ulrich, Montoro, Luís, Licchelli, Domenico, Perez, Alex Escartin, Perez, Carlos Perelló, Deldem, Marc, Futcher, Stephen R. L., Nelson, Tim, Dvorak, Shawn, Moździerski, Dawid, Quinn, Nick, Kotysz, Krzysztof, Kowalska, Katarzyna, Mikołajczyk, Przemysław, Fleming, George, Phillips, Mark, Vale, Tony, Dubois, Franky, Logie, Ludwig, Rau, Steve, Vanaverbeke, Siegfried, Merrikin, Barry, Mañanes, Esteban Fernández, Erdelyi, Emery, Carballo, Juan-Luis Gonzalez, Martinez, Fernando Limon, Long, Timothy P., Segundo Delgado, Adolfo San, Salto González, Josép Luis, Espasa, Luis Tremosa, Piehler, Georg, Crumpton, James, Billington, Samuel J., D’Arcy, Emma, Makin, Sally V., and Dover, Lord

Abstract

The HOYS citizen science project conducts long term, multifilter, high cadence monitoring of large YSO samples with a wide variety of professional and amateur telescopes. We present the analysis of the light curve of V1490 Cyg in the Pelican Nebula. We show that colour terms in the diverse photometric data can be calibrated out to achieve a median photometric accuracy of 0.02 mag in broadband filters, allowing detailed investigations into a variety of variability amplitudes over timescales from hours to several years. Using Gaia DR2 we estimate the distance to the Pelican Nebula to be 870 $^{+70}_{-55}$ pc. V1490 Cyg is a quasi-periodic dipper with a period of 31.447 ± 0.011 d. The obscuring dust has homogeneous properties, and grains larger than those typical in the ISM. Larger variability on short timescales is observed in U and Rc −Hα, with U-amplitudes reaching 3 mag on timescales of hours, indicating the source is accreting. The Hα equivalent width and NIR/MIR colours place V1490 Cyg between CTTS/WTTS and transition disk objects. The material responsible for the dipping is located in a warped inner disk, about 0.15 AU from the star. This mass reservoir can be filled and emptied on time scales shorter than the period at a rate of up to 10−10 M⊙/yr, consistent with low levels of accretion in other T Tauri stars. Most likely the warp at this separation from the star is induced by a protoplanet in the inner accretion disk. However, we cannot fully rule out the possibility of an AA Tau-like warp, or occultations by the Hill sphere around a forming planet.

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