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

[vsnet-campaign-dn 16087] Gaia21efs: likely CV (dwarf nova?)
by Taichi Kato 31 Oct '21

31 Oct '21

Gaia21efs: likely CV (dwarf nova?) Tonny Vanmunster reported observations. The data show 0.15 mag variations (flickering or part of early superhumps?). The object is thus unlikely a microlensing, but likely a CV. Spectroscopy is encouraged.

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[vsnet-campaign-dn 16086] OT J002656.6+284933 superhumps
by Taichi Kato 30 Oct '21

30 Oct '21

OT J002656.6+284933 superhumps (=CSS101212:002657+284933) Sano-san and Tamas Tordai have reported observations. 0.3-mag superhumps are clearly present.

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[vsnet-campaign-dn 16085] OT J002656.6+284933 superoutburst
by Taichi Kato 29 Oct '21

29 Oct '21

OT J002656.6+284933 superoutburst (=CSS101212:002657+284933) This object is known as an SU UMa star above the period gap with multiple rebrightenings. The last outburst was recorded in 2016. https://ui.adsabs.harvard.edu/abs/2017PASJ...69L...4K/abstract YYYYMMDD(UT) mag observer 20211013.6632 <159c (Yutaka Maeda) 20211014.6574 <167c (Yutaka Maeda) 20211015.6572 <165c (Yutaka Maeda) 20211017.6568 <158c (Yutaka Maeda) 20211023.5999 154:c (Yutaka Maeda) 20211025.5847 153cG (Yutaka Maeda) 20211026.5832 152:cG (Yutaka Maeda) 20211027.5983 153:cG (Yutaka Maeda)

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[vsnet-campaign-dn 16084] OGLE-MC-DN-0008: new SU UMa-type dwarf nova
by Taichi Kato 28 Oct '21

28 Oct '21

OGLE-MC-DN-0008: new SU UMa-type dwarf nova Josch Hambsch has reported observations on two nights. The object shows 0.17-mag superhumps with a period of 0.06056(8) d.

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[vsnet-campaign-dn 16083] ASASSN-21tr: superhump period
by Taichi Kato 27 Oct '21

27 Oct '21

ASASSN-21tr: superhump period Tonny Vanmunster, Tamas Tordai and Itoh-san have reported observations. The superhump period since Oct. 25 is 0.0666(2) d. The amplitude is still small (0.06 mag) and they are most likely stage A superhumps.

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[vsnet-campaign-dn 16082] XM78HT: regular superhumps
by Taichi Kato 27 Oct '21

27 Oct '21

XM78HT: regular superhumps The most recent data by Kyoto U. team on Oct. 26 detected clear ordinary superhumps. The superhumps started growing on Oct. 25 (Vihorlat Obs. team). The current period (stage A) is 0.05596(8) d.

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[vsnet-campaign-dn 16081] ASASSN-19ty: new SU UMa-type dwarf nova
by Taichi Kato 26 Oct '21

26 Oct '21

ASASSN-19ty: new SU UMa-type dwarf nova Josch Hambsch has reported observations. This object showed 0.15-mag superhump with a period of about 0.056 d.

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[vsnet-campaign-dn 16080] ASASSN-21tr: new SU UMa-type dwarf nova
by tonny.vanmunster＠gmail.com 26 Oct '21

26 Oct '21

Dear colleagues, I have been collecting unfiltered CCD observations of ASASSN-21tr over the past several nights at CBA Extremadura Observatory, using a 0.40-m f/5.1 telescope and SX-46 CCD camera under (mostly) clear skies. The collected light curves did not show obvious periodic modulations, with the exception of last night Oct 25/26, 2021. Regular superhumps with an amplitude of 0.11 mag are clearly visible, establishing ASASSN-21tr 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 0.0647 +/- 0.0012d. The object was at mag CV = 15.4 on Oct 25th. 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 16079] Re: Gaia21ewd
by Taichi Kato 26 Oct '21

26 Oct '21

Re: Gaia21ewd > Is this already known? = ASASSN-21tq

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[vsnet-campaign-dn 16078] Gaia21ewd
by Taichi Kato 26 Oct '21

26 Oct '21

Gaia21ewd Is this already known? http://gsaweb.ast.cam.ac.uk/alerts/alert/Gaia21ewd/ Gaia21ewd AT2021abxz 2021-10-24 09:29:11 77.12632 -19.19769 14.03 21.04 0.09 unknown 2021-10-25 07:39:47 UV and Gaia source in 7 mag outburst, candidate CV

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