July 2022 - vsnet-alert - ooruri.kusastro.kyoto-u.ac.jp

[vsnet-alert 26797] ASASSN-22ho: new SU UMa-type dwarf nova

by tonny.vanmunster＠gmail.com

Dear colleagues, I have just finished analysing my unfiltered CCD observations of ASASSN-22ho, obtained on 2022, June 02/03 at CBA Belgium Observatory, using a 0.40-m f/10.0 telescope and QHY-286M CMOS camera under clear skies. Regular superhumps with an amplitude of 0.35 mag are very clearly visible in the resulting light curve, establishing ASASSN-22ho 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 (long) superhump period of 0.0902 +/- 0.0025d. The object was at mag CV = 16.5 on Jun 03rd. 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

6 months, 1 week

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[vsnet-alert 26865] TCP J22561804+4109534: new WZ Sge-type dwarf nova

by tonny.vanmunster＠gmail.com

Dear colleagues, I have just finished analysing my unfiltered CCD observations of TCP J22561804+4109534, obtained on 2022, July 04/05 at CBA Belgium Observatory, using a 0.40-m f/10.0 telescope and QHY-286M CMOS camera under clear skies. I have been observing this object during multiple nights between June 27th and now. On all previous nights, no obvious modulations were visible in the light curve, except for last night when superhumps with an amplitude of 0.14 mag became very clearly visible. A period analysis using the ANOVA, Lomb-Scargle, Generalized-Lomb-Scargle and PDM methods (Peranso 3.0), yields a combined superhump period of 0.0650 +/- 0.0011d. The object was at mag CV = 15.3 on Jul 05th. The superhump profile shows no signs of a double-waved pattern, and I could not detect early superhumps in my data. Yet, the large outburst amplitude of ~7.4 mag, and the long time for superhumps to develop (approx. 9 days) make this a very likely WZ Sge-type dwarf nova. Follow-up observations are recommended to further track the evolution of the superhumps. 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 ____________________________________________________________ Center for Backyard Astrophysics (CBA) mailing lists https://cbastro.org/communications/mailing-lists/

8 months, 1 week

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[vsnet-alert 26887] Re: [VSS] V0854 CEN fading? and S Aps possible fade

by Peter Williams

Hi Marcos and All, As noted below, the RCB star V854 Cen may have commenced to decline (10x50mm binoculars): CENV854 20220717.386 74 WPX CENV854 20220724.420 73 WPX CENV854 20220727.410 74 WPX CENV854 20220728.432 75 WPX CENV854 20220730.368 81 WPX Also, the RCB star S Aps is also fainter than usual tonight and may have commenced to decline (20x80mm binoculars): APSS 20220717.418 95 WPX APSS 20220724.465 97 WPX APSS 20220727.454 97 WPX APSS 20220728.403 96 WPX APSS 20220730.429 100 WPX Further observations will confirm if either or both of these stars continue into a deep decline. Tks and regards Peter Williams Heathcote NSW From: 'Peter Williams' via Variable Stars South [mailto:VariableStarsSouth@googlegroups.com] Sent: Saturday, 30 July 2022 5:37 PM To: VariableStarsSouth(a)googlegroups.com Subject: RE: [VSS] V0854 CEN fading? Hi Marcos, V854 Cen is perhaps the most active of the RCB stars and would seem ready for a deep decline, if not overdue. I have noticed its SR variations having a marginally greater amplitude during June and July and that has in previous cases led to a decline onset. My most recent observation was on Thursday, July 28.432UT at magnitude 7.5. That is marginally fainter than usual and with your most recent magnitude of 7.9, it may well indicate the onset of a decline. It will sometimes stall near magnitude 8 and return to maximum but if it goes below magnitude 8.5 then a deep decline is most likely underway. Hopefully the twilight clouds will clear tonight! Tks and regards Peter Williams From: variablestarssouth(a)googlegroups.com <mailto:variablestarssouth@googlegroups.com> [mailto:variablestarssouth@googlegroups.com] On Behalf Of Marcos Silva Sent: Saturday, 30 July 2022 8:03 AM To: Variable Stars South <VariableStarsSouth(a)googlegroups.com <mailto:VariableStarsSouth@googlegroups.com> > Subject: [VSS] V0854 CEN fading? Dear VSS friends, last night i observed the RCB star V0854 Cen fainter than the comparison star of mag 7.5. I have observed it here again now and estimated the magnitude of 7.9, we have some cirrus here at the moment, so the star could be a little bit brighter (7.8 or 7.7). But it is still fainter than 7.5 and brighter than 8.2. I'm warning you because this could be the beginning of a fading of the star. -- You received this message because you are subscribed to the Google Groups "Variable Stars South" group. To unsubscribe from this group and stop receiving emails from it, send an email to VariableStarsSouth+unsubscribe(a)googlegroups.com <mailto:VariableStarsSouth+unsubscribe@googlegroups.com> . To view this discussion on the web, visit https://groups.google.com/d/msgid/VariableStarsSouth/fac2f5ce-2d73-4872-bd5… <https://groups.google.com/d/msgid/VariableStarsSouth/fac2f5ce-2d73-4872-bd5…> . -- You received this message because you are subscribed to the Google Groups "Variable Stars South" group. To unsubscribe from this group and stop receiving emails from it, send an email to VariableStarsSouth+unsubscribe(a)googlegroups.com <mailto:VariableStarsSouth+unsubscribe@googlegroups.com> . To view this discussion on the web, visit https://groups.google.com/d/msgid/VariableStarsSouth/000001d8a3e7%2420fb1b9… <https://groups.google.com/d/msgid/VariableStarsSouth/000001d8a3e7%2420fb1b9…> .

10 months, 1 week

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[vsnet-alert 26886] Re: Var Ret 2005 likely superoutburst

by Taichi Kato

> This long outburst began between 2022 July 16 and 21. It was > observed at mag. 13 for five days, followed by a rapid fading > on July 27. The outburst was considerably longer than short > outbursts of this dwarf nova, but shorter than standard UGSU > superoutbursts (~14 days). Might be an EI Psc star, although the peak M_V is not too faint.

10 months, 1 week

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[vsnet-alert 26885] Var Ret 2005 likely superoutburst

by Patrick Schmeer

Variable Reticuli 2005 (UGSU:) https://www.aavso.org/vsx/index.php?view=detail.top&oid=161100 Recent ASAS-SN Sky Patrol (Shappee et al. 2014ApJ...788...48S and Kochanek et al. 2017PASP..129j4502K) light curve and data: https://asas-sn.osu.edu/sky-patrol/coordinate/38d59ff4-1572-40ef-a0c5-e280e… This long outburst began between 2022 July 16 and 21. It was observed at mag. 13 for five days, followed by a rapid fading on July 27. The outburst was considerably longer than short outbursts of this dwarf nova, but shorter than standard UGSU superoutbursts (~14 days). Regards, Patrick

10 months, 1 week

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[vsnet-alert 26884] MASTER OT J001204.00-412337.4: possible WZ Sge star

by Taichi Kato

MASTER OT J001204.00-412337.4: possible WZ Sge star https://www.wis-tns.org/object/2022pel ASAS-SN data: https://asas-sn.osu.edu/sky-patrol/coordinate/de867b05-f575-4a12-abde-cbb71…

10 months, 2 weeks

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[vsnet-alert 26883] TCP J22561804+4109534 rebrightenings

by Taichi Kato

TCP J22561804+4109534 rebrightenings Tamas Tordai has reported further observations. Five rebrightenings have been recorded up to July 24. The amplitudes, however, are decreasing and frequent small-amplitude rebrightenings resemble those of WZ Sge. This phenomenon is atypical for this orbital period.

10 months, 2 weeks

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[vsnet-alert 26448] ASASSN-13cx outburst

by 前田豊

UGSU+E ASASSN-13cx outburst. ASASSN-13cx 20211118.57382 151:c Mdy.VSOLJ MAEDA Yutaka Nagasaki Japan

10 months, 2 weeks

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[vsnet-alert 26878] V919 Sgr

by Berto Monard

The symbiotic star V619 Sgr is undergoing a new outburst and has now reached a magnitude of 10.66V. It shows a similar brightness and brightening pattern as during the last such outburst, exactly 15 years ago. Berto Monard / KKO

10 months, 2 weeks

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[vsnet-alert 26877] TCP J22561804+4109534 third rebrightening

by Taichi Kato

TCP J22561804+4109534 third rebrightening Tamas Tordai and Itoh-san recorded the third rebrightening on July 21.

10 months, 2 weeks

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2023

2022

2021

vsnet-alert July 2022