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We catalog the 443 bright supernovae discovered by the All-Sky Automated Survey for Supernovae (ASAS-SN) in $2018-2020$ along with the 519 supernovae recovered by ASAS-SN and 516 additional $m_{peak}\leq18$ mag supernovae missed by ASAS-SN. Our statistical analysis focuses primarily on the 984 supernovae discovered or recovered in ASAS-SN $g$-band observations. The complete sample of 2427 ASAS-SN supernovae includes earlier $V$-band samples and unrecovered supernovae. For each supernova, we identify the host galaxy, its UV to mid-IR photometry, and the offset of the supernova from the center of the host. Updated light curves, redshifts, classifications, and host galaxy identifications supersede earlier results. With the increase of the limiting magnitude to $g\leq18$ mag, the ASAS-SN sample is roughly complete up to $m_{peak}=16.7$ mag and is $90\%$ complete for $m_{peak}\leq17.0$ mag. This is an increase from the $V$-band sample where it was roughly complete up to $m_{peak}=16.2$ mag and $70\%$ complete for $m_{peak}\leq17.0$ mag., Comment: 14 pages, 7 figures, 4 tables. Updated to reflect changes made in the published version. Tables containing the catalog data presented in this submission are included in machine-readable format as ancillary files

We present the result of a multi-longitude campaign on the photometric study of the dwarf nova ASASSN-18fk during its superoutburst in 2018. It was observed with 18 telescopes at 15 sites during ~70 nights within a three-month interval. Observations covered the main outburst, six rebrightenings and 50-d decline to a near-quiescent state. We identify ASASSN-18fk as WZ Sge-type dwarf nova with multiple rebrightenings and show the evolution of the 0.06-d superhump period over all stages of the superoutburst. A strong 22-min brightness modulation that superimposed on superhumps is found during rebrightenings and decline. Some evidence of this modulation in a form of a sideband signal is detected during the very onset of the outburst. We interpret the 22-min modulation as a spin period of the white dwarf and suggest that ASASSN-18fk is a good candidate for a superhumping intermediate polar., Comment: 12 pages, 8 figures

UX Orionis stars (UXors) are Herbig Ae/Be or T Tauri stars exhibiting sporadic occultation of stellar light by circumstellar dust. GM\,Cephei is such a UXor in the young ($\sim4$~Myr) open cluster Trumpler\,37, showing prominent infrared excess, emission-line spectra, and flare activity. Our photometric monitoring (2008--2018) detects (1)~an $\sim$3.43~day period, likely arising from rotational modulation by surface starspots, (2)~sporadic brightening on time scales of days due to accretion, (3)~irregular minor flux drops due to circumstellar dust extinction, and (4)~major flux drops, each lasting for a couple of months with a recurrence time, though not exactly periodic, of about two years. The star experiences normal reddening by large grains, i.e., redder when dimmer, but exhibits an unusual "blueing" phenomenon in that the star turns blue near brightness minima. The maximum extinction during relatively short (lasting $\leq 50$~days) events, is proportional to the duration, a consequence of varying clump sizes. For longer events, the extinction is independent of duration, suggestive of a transverse string distribution of clumps. Polarization monitoring indicates an optical polarization varying $\sim3\%$--8$\%$, with the level anticorrelated with the slow brightness change. Temporal variation of the unpolarized and polarized light sets constraints on the size and orbital distance of the circumstellar clumps in the interplay with the young star and scattering envelope. These transiting clumps are edge-on manifestations of the ring- or spiral-like structures found recently in young stars with imaging in infrared of scattered light, or in submillimeter of thermalized dust emission., Comment: 20 pages, 9 figures

In this catalog we compile information for all supernovae discovered by the All-Sky Automated Survey for SuperNovae (ASAS-SN) as well as all other bright ($m_{peak}\leq17$), spectroscopically confirmed supernovae found in 2017, totaling 308 supernovae. We also present UV through near-IR magnitudes gathered from public databases of all host galaxies for the supernovae in the sample. We perform statistical analyses of our full bright supernova sample, which now contains 949 supernovae discovered since 2014 May 1, including supernovae from our previous catalogs. This is the fourth of a series of yearly papers on bright supernovae and their hosts from the ASAS-SN team, and this work presents updated data and measurements, including light curves, redshifts, classifications, and host galaxy identifications, that supersede information contained in any previous publications., Comment: 14 pages, 6 figures, 4 tables. Updated to reflect changes made in the published version. Tables containing the catalog data presented in this submission are included in machine-readable format as ancillary files

Since its discovery in 2008, the Andromeda galaxy nova M31N 2008-12a has been observed in eruption every single year. This unprecedented frequency indicates an extreme object, with a massive white dwarf and a high accretion rate, which is the most promising candidate for the single-degenerate progenitor of a type-Ia supernova known to date. The previous three eruptions of M31N 2008-12a have displayed remarkably homogeneous multi-wavelength properties: (i) From a faint peak, the optical light curve declined rapidly by two magnitudes in less than two days; (ii) Early spectra showed initial high velocities that slowed down significantly within days and displayed clear He/N lines throughout; (iii) The supersoft X-ray source (SSS) phase of the nova began extremely early, six days after eruption, and only lasted for about two weeks. In contrast, the peculiar 2016 eruption was clearly different. Here we report (i) the considerable delay in the 2016 eruption date, (ii) the significantly shorter SSS phase, and (iii) the brighter optical peak magnitude (with a hitherto unobserved cusp shape). Early theoretical models suggest that these three different effects can be consistently understood as caused by a lower quiescence mass-accretion rate. The corresponding higher ignition mass caused a brighter peak in the free-free emission model. The less-massive accretion disk experienced greater disruption, consequently delaying re-establishment of effective accretion. Without the early refueling, the SSS phase was shortened. Observing the next few eruptions will determine whether the properties of the 2016 outburst make it a genuine outlier in the evolution of M31N 2008-12a., Comment: 42 pages (28 pages main paper + appendix), 16 figures, 10 tables; accepted for publication in ApJ

We present photometric and spectroscopic follow-up observations of the highly luminous Type Ibn supernova ASASSN-14ms, which was discovered on UT 2014-12-26.61 at $m_V \sim 16.5$. With a peak absolute $V$-band magnitude brighter than $-20.5$, a peak bolometric luminosity of $1.7 \times 10^{44}$ ergs s$^{-1}$, and a total radiated energy of $2.1 \times 10^{50}$ ergs, ASASSN-14ms is one of the most luminous Type Ibn supernovae yet discovered. In simple models, the most likely power source for this event is a combination of the radioactive decay of $^{56}$Ni and $^{56}$Co at late times and the interaction of supernova ejecta with the progenitor's circumstellar medium at early times, although we cannot rule out the possibility of a magnetar-powered light curve. The presence of a dense circumstellar medium is indicated by the intermediate-width He I features in the spectra. The faint ($m_g \sim 21.6$) host galaxy SDSS J130408.52+521846.4 has an oxygen abundance below $12+\log(O/H) \lesssim 8.3$, a stellar mass of $M_* \sim 2.6 \times 10^8 M_{\odot}$, and a star formation rate of $\textrm{SFR} \sim 0.02$ $M_{\odot}$ yr$^{-1}$., Comment: 12 pages, 2 tables, 6 figures. Photometric data presented in this submission are included as ancillary files. For a brief video explaining this paper, see https://www.youtube.com/watch?v=I9Maq9Q6u1g

This catalog summarizes information for all supernovae discovered by the All-Sky Automated Survey for SuperNovae (ASAS-SN) and all other bright ($m_{peak}\leq17$), spectroscopically confirmed supernovae discovered in 2016. We then gather the near-IR through UV magnitudes of all host galaxies and the offsets of the supernovae from the centers of their hosts from public databases. We illustrate the results using a sample that now totals 668 supernovae discovered since 2014 May 1, including the supernovae from our previous catalogs, with type distributions closely matching those of the ideal magnitude limited sample from Li et al. (2011). This is the third of a series of yearly papers on bright supernovae and their hosts from the ASAS-SN team., Comment: 15 pages, 6 figures, 4 tables. Manuscript updated to reflect changes made in the published version. Tables containing the catalog data presented in this submission are included in machine-readable format as ancillary files. For a brief video explaining this paper, see https://youtu.be/LGm3NVO9yz0

This manuscript presents information for all supernovae discovered by the All-Sky Automated Survey for SuperNovae (ASAS-SN) during 2015, its second full year of operations. The same information is presented for bright ($m_V\leq17$), spectroscopically confirmed supernovae discovered by other sources in 2015. As with the first ASAS-SN bright supernova catalog, we also present redshifts and near-UV through IR magnitudes for all supernova host galaxies in both samples. Combined with our previous catalog, this work comprises a complete catalog of 455 supernovae from multiple professional and amateur sources, allowing for population studies that were previously impossible. This is the second of a series of yearly papers on bright supernovae and their hosts from the ASAS-SN team., Comment: 16 pages, 6 figures, 4 tables. Submitted to MNRAS. Tables containing the catalog data presented in this submission are included in machine-readable format as ancillary files. Manuscript updated to reflect changes made in the published version and to correct an error in the host galaxy magnitudes presented in Tables 3 and 4. For a brief video explaining this paper, see https://youtu.be/iqYJp1AmyMw

The Andromeda Galaxy recurrent nova M31N 2008-12a had been observed in eruption ten times, including yearly eruptions from 2008-2014. With a measured recurrence period of $P_\mathrm{rec}=351\pm13$ days (we believe the true value to be half of this) and a white dwarf very close to the Chandrasekhar limit, M31N 2008-12a has become the leading pre-explosion supernova type Ia progenitor candidate. Following multi-wavelength follow-up observations of the 2013 and 2014 eruptions, we initiated a campaign to ensure early detection of the predicted 2015 eruption, which triggered ambitious ground and space-based follow-up programs. In this paper we present the 2015 detection; visible to near-infrared photometry and visible spectroscopy; and ultraviolet and X-ray observations from the Swift observatory. The LCOGT 2m (Hawaii) discovered the 2015 eruption, estimated to have commenced at Aug. $28.28\pm0.12$ UT. The 2013-2015 eruptions are remarkably similar at all wavelengths. New early spectroscopic observations reveal short-lived emission from material with velocities $\sim13000$ km s$^{-1}$, possibly collimated outflows. Photometric and spectroscopic observations of the eruption provide strong evidence supporting a red giant donor. An apparently stochastic variability during the early super-soft X-ray phase was comparable in amplitude and duration to past eruptions, but the 2013 and 2015 eruptions show evidence of a brief flux dip during this phase. The multi-eruption Swift/XRT spectra show tentative evidence of high-ionization emission lines above a high-temperature continuum. Following Henze et al. (2015a), the updated recurrence period based on all known eruptions is $P_\mathrm{rec}=174\pm10$ d, and we expect the next eruption of M31N 2008-12a to occur around mid-Sep. 2016., Comment: 46 pages, 19 figures, 14 tables, accepted for publication in ApJ (accepted version, minor changes made during the refereeing process)

We present basic statistics for all supernovae discovered by the All-Sky Automated Survey for SuperNovae (ASAS-SN) during its first year-and-a-half of operations, spanning 2013 and 2014. We also present the same information for all other bright ($m_V\leq17$), spectroscopically confirmed supernovae discovered from 2014 May 1 through the end of 2014, providing a comparison to the ASAS-SN sample starting from the point where ASAS-SN became operational in both hemispheres. In addition, we present collected redshifts and near-UV through IR magnitudes, where available, for all host galaxies of the bright supernovae in both samples. This work represents a comprehensive catalog of bright supernovae and their hosts from multiple professional and amateur sources, allowing for population studies that were not previously possible because the all-sky emphasis of ASAS-SN redresses many previously existing biases. In particular, ASAS-SN systematically finds bright supernovae closer to the centers of host galaxies than either other professional surveys or amateurs, a remarkable result given ASAS-SN's poorer angular resolution. This is the first of a series of yearly papers on bright supernovae and their hosts that will be released by the ASAS-SN team., Comment: 14 pages, 6 figures, 4 tables. Tables containing the catalog data presented in this submission are included in machine-readable format as ancillary files. Manuscript updated to reflect changes made in the published version. For a brief video explaining this paper, see https://youtu.be/jmlDUcpI_-s

We present the results of the spectroscopic and photometric monitoring campaign of ASASSN-15ed. The transient was discovered quite young by the All Sky Automated Survey for SuperNovae (ASAS-SN). Amateur astronomers allowed us to sample the photometric SN evolution around maximum light, which we estimate to have occurred on JD = 2457087.4 +- 0.6 in the r-band. Its apparent r-band magnitude at maximum was r = 16.91 +- 0.10, providing an absolute magnitude M(r) ~ -20.04 +- 0.20, which is slightly more luminous than the typical magnitudes estimated for Type Ibn SNe. The post-peak evolution was well monitored, and the decline rate (being in most bands around 0.1 mag/d during the first 25 d after maximum) is marginally slower than the average decline rates of SNe Ibn during the same time interval. The object was initially classified as a Type Ibn SN because early-time spectra were characterized by a blue continuum with superimposed narrow P-Cygni lines of He I, suggesting the presence of a slowly moving (1200-1500 km/s), He-rich circumstellar medium. Later on, broad P-Cygni He I lines became prominent. The inferred velocities, as measured from the minimum of the broad absorption components, were between 6000 and 7000 km/s. As we attribute these broad features to the SN ejecta, this is the first time we have observed the transition of a Type Ibn SN to a Type Ib SN., Comment: 14 pages, 7 figures, 4 tables; published by MNRAS

On 2014 Dec. 9.61, the All-Sky Automated Survey for SuperNovae (ASAS-SN or "Assassin") discovered ASASSN-14lp just $\sim2$ days after first light using a global array of 14-cm diameter telescopes. ASASSN-14lp went on to become a bright supernova ($V = 11.94$ mag), second only to SN 2014J for the year. We present prediscovery photometry (with a detection less than a day after first light) and ultraviolet through near-infrared photometric and spectroscopic data covering the rise and fall of ASASSN-14lp for more than 100 days. We find that ASASSN-14lp had a broad light curve ($\Delta m_{15}(B) = 0.80 \pm 0.05$), a $B$-band maximum at $2457015.82 \pm 0.03$, a rise time of $16.94^{+ 0.11 }_{- 0.10 }$ days, and moderate host--galaxy extinction ($E(B-V)_{\textrm{host}} = 0.33 \pm 0.06$). Using ASASSN-14lp we derive a distance modulus for NGC 4666 of $\mu = 30.8 \pm 0.2$ corresponding to a distance of $14.7 \pm 1.5$ Mpc. However, adding ASASSN-14lp to the calibrating sample of Type Ia supernovae still requires an independent distance to the host galaxy. Finally, using our early-time photometric and spectroscopic observations, we rule out red giant secondaries and, assuming a favorable viewing angle and explosion time, any non-degenerate companion larger than $0.34 R_{\textrm{sun}}$., Comment: 12 pages, 9 figures, 4 tables. Accepted to ApJ. Photometric data presented in this submission are included as an ancillary file. For a brief video explaining this paper, see https://www.youtube.com/watch?v=1bOV-Cqs-ag

We report the discovery of ASASSN-15lh (SN 2015L), which we interpret as the most luminous supernova yet found. At redshift z = 0.2326, ASASSN-15lh reached an absolute magnitude of M_{u,AB} = -23.5+/-0.1 and bolometric luminosity L_bol = (2.2+/-0.2)x 10^45 ergs s^-1, which is more than twice as luminous as any previously known supernova. It has several major features characteristic of the hydrogen-poor super-luminous supernovae (SLSNe-I), whose energy sources and progenitors are currently poorly understood. In contrast to most previously known SLSNe-I that reside in star-forming dwarf galaxies, ASASSN-15lh appears to be hosted by a luminous galaxy (M_K ~ -25.5) with little star formation. In the 4 months since first detection, ASASSN-15lh radiated (1.1+/- 0.2)x10^52 ergs, challenging the magnetar model for its engine., Comment: Published in the January 15, 2016 Issue of Science Magazine

The Andromeda Galaxy recurrent nova M31N 2008-12a had been caught in eruption eight times. The inter-eruption period of M31N 2008-12a is ~1 year, making it the most rapidly recurring system known, and a strong single-degenerate Type Ia Supernova progenitor candidate. Following the 2013 eruption, a campaign was initiated to detect the predicted 2014 eruption and to then perform high cadence optical photometric and spectroscopic monitoring using ground-based telescopes, along with rapid UV and X-ray follow-up with the Swift satellite. Here we report the results of a high cadence multicolour optical monitoring campaign, the spectroscopic evolution, and the UV photometry. We also discuss tantalising evidence of a potentially related, vastly-extended, nebulosity. The 2014 eruption was discovered, before optical maximum, on October 2, 2014. We find that the optical properties of M31N 2008-12a evolve faster than all Galactic recurrent novae known, and all its eruptions show remarkable similarity both photometrically and spectroscopically. Optical spectra were obtained as early as 0.26 days post maximum, and again confirm the nova nature of the eruption. A significant deceleration of the inferred ejecta expansion velocity is observed which may be caused by interaction of the ejecta with surrounding material, possibly a red giant wind. We find a low ejected mass and low ejection velocity, which are consistent with high mass-accretion rate, high mass white dwarf, and short recurrence time models of novae. We encourage additional observations, especially around the predicted time of the next eruption, towards the end of 2015., Comment: 23 pages, 11 figures, 5 tables, accepted for publication in Astronomy & Astrophysics

We report optical photometric observations of four superoutbursts of the short-period dwarf nova TV Crv. This object experiences two types of superoutbursts; one with a precursor and the other without. The superhump period and period excess of TV Crv are accurately determined to be 0.065028 +/- 0.000008 d and 0.0342 +/- 0.0021, respectively. This large excess implies a relatively large mass ratio of the binary components (M_2/M_1), though it has a short orbital period. The two types of superoutbursts can be explained by the thermal-tidal instability model for systems having large mass ratios. Our observations reveal that superhump period derivatives are variable in distinct superoutbursts. The variation is apparently related to the presence or absence of a precursor. We propose that the superhump period derivative depends on the maximum disk radius during outbursts. We investigate the relationship of the type of superoutbursts and the superhump period derivative for known sources. In the case of superoutbursts without a precursor, superhump period derivatives tend to be larger than those in precursor-main type superoutbursts, which is consistent with our scenario., Comment: 13 pages, 11 figures, accepted for publication in A&A

We report on the results of the QW Ser campaign which has been continued from 2000 to 2003 by the VSNET collaboration team. Four long outbursts and many short ones were caught during this period. Our intensive photometric observations revealed superhumps with a period of 0.07700(4) d during all four superoutbursts, proving the SU UMa nature of this star. The recurrence cycles of the normal outbursts and the superoutbursts were measured to be $\sim$50 days and 240(30) days, respectively. The change rate of the superhump period was -5.8x10^{-5}. The distance and the X-ray luminosity in the range of 0.5-2.4 keV are estimated to be 380(60) pc and log L_x = 31.0 \pm 0.1 erg s^{-1}. These properties have typical values for an SU UMa-type dwarf nova with this superhump period., Comment: 9 pages, 12 figures, to appear in the VSNET special issue of PASJ

V4444 Sgr (Nova Sgr 1999) has been recently suggested to be a possible recurrent nova based on the detection of the preexisting dust, which may have been formed in a previous outburst. We examined this possibility using the available outburst observations, including the VSNET observations. We also noticed that this nova was recorded in the OGLE II public photometric database, which covered both preoutburst and late decline phases. The outburst light curve constructed from these observations showed a plateau phase, particularly in the OGLE II I-band light curve, which was followed by a more rapid decline. The light curve resembled those of "fast" recurrent novae and candidates in the presence of the distinct plateau phase. The outburst spectrum and the preoutburst magnitude more resembled those of classical novae, but they do not exclude the possibility of a recurrent nova., Comment: 5 pages, 6 figures, to appear in PASJ

The black hole X-ray binary V4641 Sgr experienced an outburst in 2002 May which was detected at X-ray, optical, and radio wavelengths. The outburst lasted for only 6 days, but the object remained active for the next several months. Here we report on the detailed properties of light curves during the outburst and the post-outburst active phase. We reveal that rapid optical variations of ~100 s became more prominent when a thermal flare weakened and the optical spectrum flattened in the Ic, Rc, and V-band region. In conjunction with the flat spectrum in the radio range, this strongly indicates that the origin of rapid variations is not thermal emission, but synchrotron emission. Just after the outburst, we detected repeated flares at optical and X-ray wavelengths. The optical and X-ray light curves exhibited a strong correlation, with the X-rays, lagging by about 7 min. The X-ray lag can be understood in terms of a hot region propagating into the inner region of the accretion flow. The short X-ray lag, however, requires modifications of this simple scenario to account for the short propagation time. We also detected rapid optical variations with surprisingly high amplitude 50 days after the outburst, which we call optical flashes. During the most prominent optical flash, the object brightened by 1.2 mag only within 30 s. The released energy indicates that the emission source should be at the innermost region of the accretion flow., Comment: 17 pages, 11 figures, PASJ accepted

After 10 years of quiescence, HV Vir underwent a superoutburst in January 2002. We report time-series observations clearly revealing the period change of ordinary superhumps during the superoutburst. We derived a mean superhump period of 0.058260 d and a positive period derivative of $7 \times 10^{-5}$. These results are in good agreement with the value obtained from the 1992 superoutburst. We also detected early superhumps, which were not clearly recognized in the past outburst, and a possible rebrightening. Both of them are the common characteristics of WZ Sge-type stars., Comment: 9 pages, 8 figures. Accepted for publication in PASJ

We observed the 2002 October-November outburst of the dwarf nova CW Mon. The outburst showed a clear signature of a premaximum halt, and a more rapid decline after reaching the outburst maximum. On two separate occasions, during the premaximum stage and near the outburst maximum, shallow eclipses were recorded. This finding confirms the previously suggested possibility of the grazing eclipsing nature of this system. The separate occurrence of the eclipses and the premaximum halt can be understood as a result of a combination of two-step ignition of an outburst and the inside-out propagation of the heating wave. We detected a coherent short-period (0.02549 d) signal on two subsequent nights around the optical maximum. This signal was likely present during the maximum phase of the 2000 January outburst. We interpret this signal as a signature of the intermediate polar (IP) type pulses. The rather strange outburst properties, strong and hard X-ray emission, and the low luminosity of the outburst maximum might be understood as consequences of the supposed IP nature. The ratio between the suggested spin period and the orbital period, however, is rather unusual for a system having an orbital period of ~0.176 d., Comment: 11 pages, 11 figures, to appear in PASJ

We photometrically observed three dwarf novae V877 Ara, KK Tel and PU CMa. We discovered undisputed presence of superhumps in V877 Ara and KK Tel, with mean periods of 0.08411(2) d and 0.08808(3) d, respectively. Both V877 Ara and KK Tel are confirmed to belong to long-period SU UMa-type dwarf novae. In V877 Ara, we found a large decrease of the superhump period (dot(P)/P = -14.5 +/- 2.1 x 10^(-5)). There is evidence that the period of KK Tel decreased at a similar or a more exceptional rate. Coupled with the past studies of superhump period changes, these findings suggest that a previously neglected diversity of phenomena is present in long-period SU UMa-type dwarf novae. The present discovery of a diversity in long-period SU UMa-type systems would become an additional step toward a full understanding the dwarf nova phenomenon. PU CMa is shown to be an excellent candidate for an SU UMa-type dwarf nova. We examined the outburst properties of these dwarf novae, and derived characteristic outburst recurrence times. Combined with the recently published measurement of the orbital period of PU CMa, we propose that PU CMa is the first object filling the gap between the extreme WZ Sge-type and ER UMa-type stars., Comment: 12 pages, 14 figures, accepted for publication in MNRAS

V838 Mon is marking one of the most mysterious stellar outbursts on record. The spectral energy distribution of the progenitor resembles an under-luminous F main sequence star (at V=15.6 mag), that erupted into a cool supergiant following a complex and multi-maxima lightcurve (peaking at V=6.7 mag). The outburst spectrum show BaII, LiI and lines of several s-elements, with wide P-Cyg profiles and a moderate and retracing emission in the Balmer lines. A light-echo discovered expanding around the object helped to constrain the distance (d=790+/-30 pc), providing M_V=+4.45 in quiescence and M_V=-4.35 at optical maximum (somewhat dependent on the still uncertain E(B-V)=0.5 reddening). The general outburst trend is toward lower temperatures and larger luminosities, and continuing so at the time of writing. The object properties conflict with a classification within already existing categories: the progenitor was not on a post-AGB track and thus the similarities with the born-again AGB stars FG Sge, V605 Aql and Sakurai's object are limited to the cool giant spectrum at maximum; the cool spectrum, the moderate wind velocity (500 km/sec and progressively reducing) and the monotonic decreasing of the low ionization condition argues against a classical nova scenario. The closest similarity is with a star that erupted into an M-type supergiant discovered in M31 by Rich et al. (1989), that became however much brighter by peaking at M_V=-9.95, and with V4332 Sgr that too erupted into an M-type giant (Martini et al. 1999) and that attained a lower luminosity, closer to that of V838 Mon. M31-RedVar, V4332 Sgr and V838 Mon could be manifestations of the same and new class of astronomical objects., Comment: A&A, in press