October 2021 - vsnet-campaign-dn - ooruri.kusastro.kyoto-u.ac.jp

[vsnet-campaign-dn 16047] Re: ASASSN-14cc
by Patrick Schmeer 15 Oct '21

15 Oct '21

ASASSN-14cc (AM CVn star) https://www.aavso.org/vsx/index.php?view=detail.top&oid=398940 Apparently not much activity in recent months: after a normal outburst on 2021 May 23, the only recorded brightening was a double outburst on August 4-10 and 13-18, according to ASAS-SN Sky Patrol (Shappee et al. 2014ApJ...788...48S and Kochanek et al. 2017PASP..129j4502K) data. https://asas-sn.osu.edu/sky-patrol/coordinate/d031a323-285e-44df-9854-81a0e… Regards, Patrick ------- Taichi Kato wrote on Wednesday, 28 January 2015, 07:40:45 UTC: ASASSN-14cc Let's continue observations in the next season, too. http://arxiv.org/abs/1501.06659 Title: ASASSN-14cc: Likely Helium Analog of RZ Leonis Minoris Authors: Taichi Kato (Kyoto U), Franz-Josef Hambsch (GEOS, BAV, Vereniging Voor Sterrenkunde), Berto Monard (Center for Backyard Astronomy Kleinkaroo) Categories: astro-ph.SR Comments: 5 pages, 5 figures, accepted for publication in PASJ (Letters) License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/ \\ We identified that ASASSN-14cc is a very active dwarf nova spending approximately 60% of the time in outburst. Our long-term photometry revealed that the object shows long outbursts recurring with a period of 21-33 d and very brief short outbursts lasting less than 1 d. The maximum decline rate exceeds 2.8 mag/d. The duration of long outbursts is 9-18 d, comprising 50-60% of the recurrence time of long outbursts. We detected 0.01560-0.01562 d (22.5 min) modulations during long outbursts, which we identified to be superhumps. These features indicate that ASASSN-14cc has outburst parameters very similar to the extreme dwarf nova RZ LMi but with a much shorter superhump period. All the observations can be naturally understood considering that this object is a helium analog (AM CVn-type object) of RZ LMi. The highest outburst activity among AM CVn-type objects can be understood as the high-mass transfer rate expected for the orbital period giving a condition close to the stability limit of the accretion disk. In contrast to RZ LMi, this object shows little evidence for premature quenching of the superoutburst, which has been proposed to explain the unusual outburst parameters in RZ LMi.

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[vsnet-campaign-dn 16046] MGAB-V233 superoutburst
by Taichi Kato 13 Oct '21

13 Oct '21

MGAB-V233 superoutburst SU UMa star with a short supercycle. YYYYMMDD(UT) mag observer 20210819.7185 164C (Masayuki Moriyama) 20210928.6116 152C (Masayuki Moriyama) 20211001.7142 153C (Masayuki Moriyama) 20211007.6637 154C (Masayuki Moriyama) 20211010.6187 153C (Masayuki Moriyama)

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[vsnet-campaign-dn 16045] CRTS J014709.7+171520 superoutburst
by Taichi Kato 13 Oct '21

13 Oct '21

CRTS J014709.7+171520 superoutburst YYYYMMDD(UT) mag observer 20211003.7630 <161c (Yutaka Maeda) 20211004.7184 <163c (Yutaka Maeda) 20211005.7076 <167c (Yutaka Maeda) 20211006.7022 <164c (Yutaka Maeda) 20211007.7002 149cG (Yutaka Maeda) 20211008.842 15.24C (Gary Poyner) 20211008.8440 14.77C (Masao Funada) 20211009.3620 15.096zg (Zwicky Transient Facility Lasair (Masci+ 2019)) 20211009.8576 15.31C (Masao Funada) 20211010.6022 150cG (Yutaka Maeda) 20211011.3231 15.397zr (Zwicky Transient Facility Lasair (Masci+ 2019)) 20211011.5900 <140c (Yutaka Maeda)

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[vsnet-campaign-dn 16044] PNV J00444033+4113068: new WZ Sge-type dwarf nova
by Taichi Kato 13 Oct '21

13 Oct '21

PNV J00444033+4113068: new WZ Sge-type dwarf nova Tamas Tordai has reported observations. The object showed large-amplitude (0.7 mag!) early superhumps with a period of 0.0553(4) d. This object must have a high inclination and further observations are very encouraged.

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[vsnet-campaign-dn 16043] ASASSN-21sz
by Taichi Kato 12 Oct '21

12 Oct '21

ASASSN-21sz ASASSN-21sz --- ------- 21:48:30.31 -35:38:49.3 2021-10-7.14 13.56 SDSS DSS VIZIER ------- CV candidate, matches to GAIA DR2 G=18.6, g>17.8 on 2021-10-05.08, g=14.0 on 2021-10-06.11, g=14.1 on 2021-10-07.17, g=14.6 on 2021-10-10.05 ASASSN-21sz 20211005.08 <178g ASN ASASSN-21sz 20211007.17 141g ASN ASASSN-21sz 20211010.05 146g ASN 214830.443 -353848.98 (2000.0) Gaia_DR2_6587981306620492672 plx=2.019(0.320) dismod=8.5 pmra=29.370(0.384) pmdec=-19.011(0.399) G=18.596 BP=18.625 RP=18.304 214830.444 -353848.99 (2000.0) Gaia_EDR3_6587981306620492672 plx=1.926(0.170) dismod=8.6 pmra=29.685(0.155) pmdec=-18.968(0.107) G=18.618 BP=18.722 RP=18.449 214831.2 -353851 (2000.0) 1RXS_J214831.3-353852 0.055 0.39 0.62

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[vsnet-campaign-dn 16042] Re: LL And rapid fading
by Patrick Schmeer 12 Oct '21

12 Oct '21

LL Andromedae (UGWZ) https://www.aavso.org/vsx/index.php?view=detail.top&oid=260 The rapid fading was already reported by me on Sept. 9 (vsnet-alert 26311). It started around 2021 September 9.1 UT according to AAVSO data: https://app.aavso.org/webobs/results/?star=000-BBB-961 Time-resolved photometry or at least daily snapshots are still encouraged. Clear skies, Patrick ------------ Filipp Romanov wrote on Monday, 11 October 2021 at 15:58:48 UTC: Based on my observations (remotely from Burke-Gaffney Observatory, Canada), rapid fading of LL And started after 2021-10-08: 2021 10 05.28754 14.76 V 2021 10 06.31925 14.84 V 2021 10 07.09830 14.94 V 2021 10 08.25946 15.06 V 2021 10 09.14966 15.50 V I reported these observations and my other multicolour photometric observations in the [vsnet-obs 94323]. With best regards, Filipp Romanov (Russia). ------------ Taichi Kato wrote on Sunday, 10 October 2021 at 23:54:33 UTC: LL And rapid fading Itoh-san's most recent observation on Sep. 10 indicated that the object faded to 17th mag. Please keep an eye on this object to look for possible rebrightening(s).

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[vsnet-campaign-dn 16041] LL And rapid fading
by Taichi Kato 11 Oct '21

11 Oct '21

LL And rapid fading Itoh-san's most recent observation on Sep. 10 indicated that the object faded to 17th mag. Please keep an eye on this object to look for possible rebrightening(s).

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[vsnet-campaign-dn 16040] ASASSN-19ax: temporary brightening
by Taichi Kato 10 Oct '21

10 Oct '21

ASASSN-19ax: temporary brightening According to Itoh-san's observations, this object showed a 1-mag brightening on Oct. 4 and 5. Similar two brightenings were apparently present in ASAS-3 and ZTF data during the 2019 Jan. superoutburst. The phenomenon appears to be different from post-superoutburst rebrightenings in WZ Sge (and a few SU UMa) stars.

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[vsnet-campaign-dn 16039] ASASSN-14lb: new SU UMa-type dwarf nova
by tonny.vanmunster＠gmail.com 10 Oct '21

10 Oct '21

Dear colleagues, I have just finished analysing my unfiltered CMOS observations of ASASSN-14lb, obtained on 2021, October 08/09 at CBA Belgium Observatory, using a 0.40-m f/10.0 telescope and QHY-268M CMOS camera under clear skies. My observations were triggered by [vsnet-alert 26304]. Regular superhumps with an amplitude of 0.28 mag are clearly visible in the resulting light curve, establishing ASASSN-14lb as a new SU UMa-type dwarf nova. A period analysis using the ANOVA, Lomb-Scargle, Generalized-Lomb-Scargle and PDM methods (Peranso 3.0), yields a combined superhump period of 0.0704 +/- 0.0006d. The object was at mag CV = 16.5 on Oct 09th. I will send my observations to AAVSO, CBA and VSNET for further analysis. Best regards Tonny --- Tonny Vanmunster CBA Belgium Observatory CBA Extremadura Observatory http://www.cbabelgium.com PERANSO : The Light Curve and Period Analysis Software http://www.peranso.com

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[vsnet-campaign-dn 15985] LL And outburst
by Taichi Kato 09 Oct '21

09 Oct '21

LL And outburst Of course, this is a top-priority target! The 2004 superoutburst occurred in June and no good observations were reported. See https://ui.adsabs.harvard.edu/abs/2004PASJ...56S.135K/abstract for the 1993 superoutburst. Determination of the superhump period is very important. YYYYMMDD(UT) mag observer 20210908.9111 <139 (Eddy Muyllaert) 20210909.701 <153 (Hiroyuki Maehara) 20210909.9424 <146 (Eddy Muyllaert) 20210910.219 <17.90C (Gary Poyner) 20210910.9257 <146 (Eddy Muyllaert) 20210910.9375 <146 (Jose Ripero) 20210911.9299 <146 (Eddy Muyllaert) 20210914.901 128C (Jeremy Shears)

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vsnet-campaign-dn October 2021