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[vsnet-campaign-dn 17503] TCP J04272195-2528038; possibly a new AM CVn star in outburst?
by Yusuke Tampo 18 Jan '25

18 Jan '25

TCP J04272195-2528038; possibly a new AM CVn star in outburst? TCP J04272195-2528038 was discovered by Y. Nakamura on 2025-01-09.4837 UT at 14.2 mag. The quiescence counterpart is g_PS1=21.09(5) mag, thus outburst amplitude is ~7 mag. http://www.cbat.eps.harvard.edu/unconf/followups/J04272195-2528038.html https://www.aavso.org/vsx/index.php?view=detail.top&oid=2391199 Itoh-san and myself using the SAAO/Lesedi telescope have reported the time-resolved observations. The SAAO data shows a possible double-peaked modulation with a period of ~42.6 min. In addition, the optical spectrum I obtained with the 1.9m telescope at the SAAO shows only the He I absorption lines, lacking any significant Balmer emission/absorption lines. Further observations are encouraged to establish its classification and determine the variation period. 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-campaign-dn 17502] TCP J17374270+4915116: new SU UMa-type dwarf nova
by tonny.vanmunster＠gmail.com 30 Dec '24

30 Dec '24

Dear colleagues, I have just finished analysing my unfiltered CCD observations of TCP J17374270+4915116, obtained over the past 7 nights between 2024, Dec 23/24 and 29/30 at CBA Extremadura Observatory (Spain) using a 0.40-m f/5.1 telescope and SX-46 CCD camera under clear skies. The object started to develop superhumps on Dec 28/29, which further developed on Dec 29/30. The resulting light curve clearly shows the presence of regular superhumps with an amplitude of 0.25 mag, establishing TCP J17374270+4915116 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 0.0589 +/- 0.0002d. The object was at mag CV = 14.6 on Dec 30th. Image calibration and photometry were done using Phoranso, which allowed me to simultaenously measure 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. With kind 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-campaign-dn 17501] TCP J03493487+3607319 (aka ASASSN-24hf): new SU UMa-type dwarf nova
by tonny.vanmunster＠gmail.com 26 Dec '24

26 Dec '24

Dear colleagues, I have just finished analysing my unfiltered CCD observations of TCP J03493487+3607319 (aka ASASSN-24hf), obtained on 2024, Dec 23/24, 24/25 and 25/26 at CBA Extremadura Observatory (Spain) 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 0.23 mag, establishing TCP J03493487+3607319 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 0.0697 +/- 0.0002d. The object was at mag CV = 16.7 on Dec 26th. Image calibration and photometry were done using Phoranso, which allowed me to simultaenously measure 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. With kind 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-campaign-dn 17500] TCP J23291172+4127354: new eclipsing WZ Sge-type dwarf nova
by Yusuke Tampo 07 Dec '24

07 Dec '24

TCP J23291172+4127354: new eclipsing WZ Sge-type dwarf nova TCP J23291172+4127354 was discovered by Y. Nakamura on 2024-12-04.5385 at 14.1 mag (unfiltered). The counterpart in Pan-STARRS1 is g= 21.6 mag (objID= 157753522991272187), hence the outburst amplitude is ~7.5 mag. http://www.cbat.eps.harvard.edu/unconf/followups/J23291172+4127354.html https://www.aavso.org/vsx/index.php?view=detail.top&oid=2390566 Time-resolved observations reported by Itoh-san on the 5th and 6th Dec show double-peaked profiles and superposed eclipses. Its period and amplitude are obtained as 0.05693(2) d and ~0.5 mag (0.3 mag hump + 0.3 mag eclipse). Thus TCP J23291172+4127354 is a new (and yet another!) eclipsing WZ Sge-type dwarf nova. This would be another nice target for time-resolved photometries. 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-campaign-dn 17498] Gaia DR3 3130088774241620608: confirmation as a WZ Sge-type dwarf nova
by Yusuke Tampo 04 Dec '24

04 Dec '24

Gaia DR3 3130088774241620608: confirmation as a WZ Sge-type dwarf nova Itoh-san and J. Hambsch have reported the time-resolved observations of Gaia DR3 3130088774241620608 = TCP J06330104+0303350. The light curve shows a large-amplitude double-hump profile and superposed eclipses. Combining with AAVSO observations by J. Zhao, I obtained the early superhump+eclipse period as 0.05786(1) d. The orbital profile amplitude is ~0.5 mag; 0.3 mag early superhump plus 0.3 mag eclipse. Therefore, Gaia DR3 3130088774241620608 is now confirmed as an eclipsing WZ Sge-type. Time-resolved observations are strongly encouraged! best regards, Yusuke 2024年11月29日(金) 15:56 Yusuke Tampo <tampo(a)kusastro.kyoto-u.ac.jp>: > > TCP J06330104+0303350 = Gaia DR3 3130088774241620608 > > TCP J06330104+0303350 was discovered by T. Kojima on 2024-11-28.76 at > 13.9 mag and now brightened to V=13.4 mag according to TOCP reports. > http://www.cbat.eps.harvard.edu/unconf/followups/J06330104+0303350.html > > This system has already been pointed as a WZ Sge-type cataclysmic > variable candidate in Inight et al 2024, named Gaia DR3 > 3130088774241620608. > https://www.aavso.org/vsx/index.php?view=detail.top&oid=2389763 > https://ui.adsabs.harvard.edu/abs/2024MNRAS.tmp.2451I/abstract > > This outburst is a great opportunity to determine its outburst nature > as well as derive its superhump periods. > Time-resolved 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 > > ---------------------------------------------- -- ---------------------------------------------- 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-campaign-dn 17497] TCP J06330104+0303350 = Gaia DR3 3130088774241620608
by Yusuke Tampo 29 Nov '24

29 Nov '24

TCP J06330104+0303350 = Gaia DR3 3130088774241620608 TCP J06330104+0303350 was discovered by T. Kojima on 2024-11-28.76 at 13.9 mag and now brightened to V=13.4 mag according to TOCP reports. http://www.cbat.eps.harvard.edu/unconf/followups/J06330104+0303350.html This system has already been pointed as a WZ Sge-type cataclysmic variable candidate in Inight et al 2024, named Gaia DR3 3130088774241620608. https://www.aavso.org/vsx/index.php?view=detail.top&oid=2389763 https://ui.adsabs.harvard.edu/abs/2024MNRAS.tmp.2451I/abstract This outburst is a great opportunity to determine its outburst nature as well as derive its superhump periods. Time-resolved 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-campaign-dn 17496] ASASSN-24gv - new SU UMa-type dwarf nova
by Yusuke Tampo 29 Nov '24

29 Nov '24

ASASSN-24gv - new SU UMa-type dwarf nova ASASSN-24gv is a new CV candidate discovered by ASAS-SN at 15.25 mag on 2024-11-25. The quiescence counterpart is the g=22.34(2) star in the YMCA catalog, thus outburst amplitude is ~7 mag. Our time-resolved observations at SAAO on 2024-11-28 detected likely superhumps with a period of ~0.06 d and amplitude of 0.12 mag, classifying ASASSN-24gv as an SU UMa-type dwarf nova. Further observations are encouraged to establish its superhump period. 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-campaign-dn 17495] ASASSN-24gm: new WZ Sge-type dwarf nova
by Yusuke Tampo 13 Nov '24

13 Nov '24

ASASSN-24gm: new WZ Sge-type dwarf nova South African Astronomical Observatory team and Josch Hambsch have reported the time-resolved observations of ASASSN-24gm. Observations on 12 Nov. at SAAO detected clear superhumps, ~16 d after its discovery by ASAS-SN on 27th Oct. The tentative superhumps period is 0.0602(1) d, while 1-d aliases are still possible. Combining its short superhump period, large outburst amplitude of 8.4 mag, and long waiting time for superhump appearance, ASASSN-24gm is likely 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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[vsnet-campaign-dn 17494] GOTO065054.49+593624.51: end of the type-E rebrighening
by Yusuke Tampo 31 Oct '24

31 Oct '24

GOTO065054.49+593624.51: end of the type-E rebrighening According to the most recent ATLAS forced photometry and AAVSO observations by Nikola Antonov, Arto Oksanen, and Klaus Wenzel, this object dimmed around 18th mag on 2024-10-30, likely an end of its type E brightening. As type-E-rebrighening systems typically show additional short-lived brightenings, daily snapshots are still encouraged. Best regards, Yusuke #ATLAS forced photometry #UTC mag band observer 20241004.59088 13.215 c atlas 20241004.59451 13.214 c atlas 20241004.61565 13.207 c atlas 20241004.63368 13.206 c atlas 20241006.61241 13.714 o atlas 20241006.63332 13.715 o atlas 20241006.63517 13.712 o atlas 20241006.64267 13.727 o atlas 20241008.60186 13.596 c atlas 20241008.60503 13.613 c atlas 20241008.62933 13.615 c atlas 20241008.64262 13.630 c atlas 20241012.56768 13.963 c atlas 20241012.57085 13.963 c atlas 20241012.57629 13.959 c atlas 20241012.59150 13.954 c atlas 20241016.57534 14.505 o atlas 20241016.57716 14.503 o atlas 20241016.59971 14.498 o atlas 20241016.60560 14.498 o atlas 20241020.46639 14.542 o atlas 20241020.47092 14.542 o atlas 20241020.47409 14.578 o atlas 20241020.50475 14.478 o atlas 20241024.52590 14.645 o atlas 20241024.52771 14.656 o atlas 20241024.53178 14.666 o atlas 20241024.54710 14.594 o atlas 20241030.54204 17.807 c atlas 20241030.55202 17.790 c atlas 20241030.55437 17.759 c atlas 20241030.56083 17.819 c atlas 20241030.56415 17.775 c atlas 20241030.56882 18.013 c atlas 20241030.57205 17.835 c atlas -- ---------------------------------------------- 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-campaign-dn 17493] 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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