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

[vsnet-alert 28026] maintenance power outrage
by Katsuki Muraoka 31 Oct '24

31 Oct '24

Dear, VSNET members, I'm Katsuki Muraoka, a M2 student of Kyoto University. I must inform you all that there will be a maintenance power outage for the Kyoto Univ. building on this weekend, so VSNET server must be shut down in advance. The shutdown is scheduled to occur around 16:00 JST on November 2nd (UTC: 07:00), and the system is scheduled to be restored at around 17:30 JST (UTC: 08:30) on November 3rd. Thank you for your cooperation. Katsuki Muraoka

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[vsnet-alert 28025] GOTO065054.49+593624.51: type-E rebrightening WZ Sge star?
by Yusuke Tampo 23 Oct '24

23 Oct '24

GOTO065054.49+593624.51: type-E rebrightening WZ Sge star? Recent time-resolved observations reported to VSNET/AAVSO, especially those by Tonny Vanmunster, David Messier, Nikola Antonov, and Ian Sharp, show growing superhumps after its recovery from the short-lived dip around 2024-10-19. Using these time-resolved observations after the dip, the superhump period is obtained as 0.06323(2) d, consistent with previous Tonny's reports to VSNET alerts. These features suggest that this ongoing brightening event is likely a type-E rebrightening (dip caused by the disk transition from early to ordinary superhumps) and thus GOTO065054.49+593624.51 would be a new period bouncer candidate showing a WZ Sge-type dwarf nova outburst. For type-E rebrightenings and period bouncers, see.g. Kimura et al 2018 https://arxiv.org/abs/1803.03179 Further observations are encouraged. best regards, Yusuke -- ---------------------------------------------- South African Astronomical Observatory, Postdoc fellow 反保雄介 Yusuke TAMPO MAIL: tampo(a)kusastro.kyoto-u.ac.jp MAIL: yusuke(a)saao.ac.za ----------------------------------------------

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[vsnet-alert 28024] GOTO065054.49+593624.51 is now optically confirmed as a new WZ Sge-type darf nova
by tonny.vanmunster＠gmail.com 18 Oct '24

18 Oct '24

Dear colleagues, I have just completed my analysis of unfiltered CCD observations of GOTO065054.49+593624.51, acquired on Oct 17/18, 2024 at the CBA Extremadura Observatory in Spain. The observations were made using a 0.40-m f/5.1 telescope and SX-46 CCD camera under moderately clear skies, though conditions were only favorable for about 2.2 hours. Since the discovery announcement by T. Killestein et al. on Oct 4, 2024 (ATEL #16842), I have been observing this object across multiple nights, during which no obvious modulations were visible in the light curve - until tonight, when GOTO065054.49+593624.51 exhibited superhumps for the first time. The superhumps displayed an amplitude of ~0.16 mag. Period analysis employing ANOVA, Lomb-Scargle, Generalized Lomb-Scargle, and PDM methods (Peranso 3.0), yielded a combined superhump period of 0.067 +/- 0.002d. Due to the limited observation window, this value remains uncertain, and I strongly recommend follow-up observations to further track the evolution of the superhumps. The object was at mag CV = 14.7 on Oct 18th. The superhump profile currently shows no indication (yet) of a double-waved pattern. The substantial outburst amplitude (> 8 mag), and the prolonged duration for superhumps to develop (approx. 13 days), in conjunction with the spectroscopic classification suggesting it is likely a WZ Sge-type CV (ATEL #16858), firmly establish this object as a new WZ Sge-type dwarf nova. Image calibration and photometry were done using my new photometry software Phoranso 1.0.5.5. I will be submitting my observations to AAVSO, CBA, and VSNET for further analysis. Best regards Tonny --- Tonny Vanmunster CBA Belgium Observatory CBA Extremadura Observatory http://www.cbabelgium.co <http://www.cbabelgium.com/> m PERANSO : The Light Curve and Period Analysis Software http://www.peranso.co <http://www.peranso.com/> m PHORANSO: Photometric Reduction and Analysis Software *** NEW *** http://www.phoranso.com <http://www.phoranso.com/>

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[vsnet-alert 28023] Gaia J154008.28-392917.6 = ASASSN-24fy: orbital period
by Kojiguchi 09 Oct '24

09 Oct '24

Gaia J154008.28-392917.6 = ASASSN-24fy: orbital period From TESS data. Porb=0.054976(1) d.

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[vsnet-alert 28022] ASASSN-24fy: new bright outburst from a known WZ Sge star candidate
by Yusuke Tampo 04 Oct '24

04 Oct '24

ASASSN-24fy: new bright outburst from a known WZ Sge star candidate ASAS-SN reported a new CV outburst candidate ASASSN-24fy discovered on 2024-10-1.99 at 11.01 mag. This system was indeed suspected to be a WZ Sge-type CV by Pala et al 2020 based on Gaia data. >Gaia J154008.28-392917.6 https://www.aavso.org/vsx/index.php?view=detail.top&oid=844362 https://ui.adsabs.harvard.edu/abs/2020MNRAS.494.3799P/abstract Time-resolved observations are encouraged to detect superhumps and confirm the outburst nature. Best regards, Yusuke -- ---------------------------------------------- South African Astronomical Observatory, Postdoc fellow 反保雄介 Yusuke TAMPO MAIL: tampo(a)kusastro.kyoto-u.ac.jp MAIL: yusuke(a)saao.ac.za ----------------------------------------------

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[vsnet-alert 28021] TCP J18173469+1803499: new SU UMa-type dwarf nova
by tonny.vanmunster＠gmail.com 02 Oct '24

02 Oct '24

Dear colleagues I have just finished analysing my unfiltered CCD observations of TCP J18173469+1803499, obtained during 4 consecutive nights between 2024, Sep 28/29 and Oct 01/02 at CBA Extremadura Observatory using a 0.40-m f/5.1 telescope and SX-46 CCD camera under clear skies. This object was detected by the New Milky Way (NMW) survey Camera-2, operating at the Astroverty astrofarm in Russia, on Sep 27th. Superhumps started to emerge in my data set of 2024, Sep 29/30, and are now clearly present in my last set of observations obtained on 2024, Oct 01/02. That light curve shows regular superhumps with an amplitude of 0.11 mag, establishing TCP J18173469+1803499 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 0.0767 +/- 0.0026d. The object was at mag CV = 13.9 on Oct 02nd. Image calibration and photometry were done using my new photometry software Phoranso 1.0.5.1 which allowed me to simultaenously measure 10 other variables present in the FOV of this new SU UMa-type dwarf nova. 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.co <http://www.cbabelgium.com/> m PERANSO : The Light Curve and Period Analysis Software http://www.peranso.co <http://www.peranso.com/> m PHORANSO: Photometric Reduction and Analysis Software *** NEW *** http://www.phoranso.com <http://www.phoranso.com/>

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[vsnet-alert 28020] V854 Cen Possible Fade
by Peter Williams 30 Sep '24

30 Sep '24

The RCB star V854 Cen has just recovered from a deep decline that lasted from January through July 2024. During September 2024 it gradually faded again to visual magnitude 8.1, but it is not clear if this is the onset of another deep decline. It has been cloudy for the past week here at Heathcote NSW , so I have been unable to confirm the current state of V854 Cen. A check on this star would be appreciated - thanks. Recent visual observations : CENV854 20240923.381 81 WPX CENV854 20240922.403 81 WPX CENV854 20240921.398 80 WPX CENV854 20240920.370 80 WPX CENV854 20240919.397 80 WPX CENV854 20240918.393 76 WPX CENV854 20240915.398 76 WPX CENV854 20240913.390 74 WPX CENV854 20240909.440 74 WPX CENV854 20240906.384 76 WPX CENV854 20240905.383 74 WPX CENV854 20240904.404 74 WPX CENV854 20240902.401 74 WPX CENV854 20240901.454 74 WPX CENV854 20240831.374 75 WPX Tks and regards Peter Williams Heathcote NSW 10x50mm binoculars

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[vsnet-alert 28019] TCP J17064645-3528079: new classical nova
by Yusuke Tampo 10 Sep '24

10 Sep '24

TCP J17064645-3528079: new classical nova TCP J17064645-3528079 was discovered by Koichi Itagaki on 2024-09-09.4363 UT at 11.4 mag. I reported the optical spectrum of TCP J17064645-3528079 to ATel and classified it as a new classical nova eruption. https://www.astronomerstelegram.org/?read=16808 Further observations are encouraged. Best regards, Yusuke -- ---------------------------------------------- South African Astronomical Observatory, Postdoc fellow Yusuke TAMPO MAIL: tampo(a)kusastro.kyoto-u.ac.jp MAIL: yusuke(a)saao.ac.za ----------------------------------------------

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[vsnet-alert 28018] ASASSN-24fq: new SU UMa-type dwarf nova
by tonny.vanmunster＠gmail.com 02 Sep '24

02 Sep '24

Dear colleagues, I have just finished analysing my unfiltered CCD observations of ASASSN-24fq, obtained on 2024, Aug 30/Sep 01 and Sep 01/02 at CBA Extremadura Observatory using a 0.40-m f/5.1 telescope and SX-46 CCD camera under clear skies. The resulting light curve clearly shows the presence of regular superhumps with an amplitude of 0.56 mag, establishing ASASSN-24fq as a new SU UMa-type dwarf nova. A period analysis, using the ANOVA, Lomb-Scargle, Generalized-Lomb-Scargle, PDM and Phase-binned AoV methods (Peranso 3.0) yields a combined superhump period of 0.0590 +/- 0.0002d. The object was at mag CV = 15.8 on Aug 13th. Image calibration and photometry were done using my new photometry software Phoranso 1.0.4.8, which allowed me to simultaenously measure several other variables present in the FOV of this new SU UMa-type dwarf nova. 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.co <http://www.cbabelgium.com/> m PERANSO : The Light Curve and Period Analysis Software http://www.peranso.co <http://www.peranso.com/> m PHORANSO: Photometric Reduction and Analysis Software *** NEW *** http://www.phoranso.com <http://www.phoranso.com/>

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[vsnet-alert 28017] ASASSN-24fo: new WZ Sge-type dwarf nova
by Yusuke Tampo 29 Aug '24

29 Aug '24

ASASSN-24fo: new WZ Sge-type dwarf nova ASASSN-24fo was discovered on 2024-08-25.14 by the ASAS-SN team with an ~8.5 mag outburst amplitude. Sjoerd Dufoer and Josch Hambsch reported time-resolved observations. These observations detected a double-waved variation with an amplitude of 0.04 mag and a period of 0.05691(5) d. Therefore ASASSN-24fo is a new WZ Sge-type dwarf nova Further observations are encouraged. Best regards, Yusuke -- ---------------------------------------------- South African Astronomical Observatory, Postdoc fellow Yusuke TAMPO MAIL: tampo(a)kusastro.kyoto-u.ac.jp MAIL: yusuke(a)saao.ac.za ----------------------------------------------

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