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

[vsnet-alert 28052] EX Hya in outburst
by Rod Stubbings 13 Mar '25

13 Mar '25

EX Hya in outburst (NLDQ(UG)+E) HYAEX 250310.486 130 HYAEX 250313.469 106 HYAEX 250313.569 106 -- Rod Stubbings Tetoora Road Observatory Victoria, Australia Honorary Associate member Astronomical Society of Australia Telescope: "Infinity" 22" f/3.8 stubbo(a)dcsi.net.au http://rodstubbingsobservatory.wordpress.com/

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[vsnet-alert 28050] TCP J14034008+7947313: new SU UMa-type dwarf nova
by tonny.vanmunster＠gmail.com 08 Mar '25

08 Mar '25

Dear colleagues, I have just finished analysing my unfiltered CCD observations of TCP J14034008+7947313, obtained over the past 7 nights between 2025, Feb 28 and Mar 06 at CBA Belgium Observatory using a 0.40-m f/10.0 telescope and QHY-268M CMOS camera under clear skies. No superhumps were visible in the light curves of this object till 2025, Mar 6/7. The light curve of 2025, Mar 6/7 clearly shows the presence of regular superhumps with an amplitude of 0.18 mag, establishing TCP J14034008+7947313 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 0.0586 +/- 0.0003d. The object was at mag CV = 15.3 on Mar 06th. Image calibration and photometry were done using Phoranso, which allows to simultaneously measure other variables present in the FOV of a variable star. 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 http://www.phoranso.com <http://www.phoranso.com/>

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[vsnet-alert 28049] TCP J07222683+6220548: AM CVn star showing a superoutburst
by Yusuke Tampo 28 Feb '25

28 Feb '25

TCP J07222683+6220548: AM CVn star showing a superoutburst The time-resolved observations of TCP J07222683+6220548 aka ZTF25aacfjde have been repoted by Itoh-san, Sano-san, Josch Hambsch and Tamás Tordai. This object showed a 4-mag dip in the middle of the outburst, and time-resolved observations by Itoh-san after the recovery from this dip detected single-peaked variations with a period of 0.03256(2) d, likely an ordinary superhump. Thus TCP J07222683+6220548 is a new AM CVn star showing a superoutburst. 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 28048] V748 Hya outburst
by Rod Stubbings 23 Feb '25

23 Feb '25

The UGWZ star V748 Hya in bright outburst. HYAV748 250223.517 120 Stu.RASNZ -- Rod Stubbings Tetoora Road Observatory Victoria, Australia Honorary Associate member Astronomical Society of Australia Telescope: "Infinity" 22" f/3.8 stubbo(a)dcsi.net.au http://rodstubbingsobservatory.wordpress.com/

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[vsnet-alert 28047] ASASSN-25ao
by Berto Monard 05 Feb '25

05 Feb '25

Hello, ASASSN-25ao, an outbursting blue object was observed at CBA-KKO on 3 and 4 Feb 2026. The object faded from an average of 15.85 to 16.16 CR (unfiltered magnitudes) over that period. The light curves showed a modulation hinting at a main period around 0.12d and a strong secondary period of 0.030d +/- 0.0005d, derived from GLS and PDM methods in Peranso. Further observations are planned for Friday 7 Feb, when skies will be clear again. Berto Monard / CBA KKO Calitzdorp, South Africa

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[vsnet-alert 28046] V4141Sgr outburst
by Tadashi Kojima 03 Feb '25

03 Feb '25

object YYYYMMDD(UT) mag V4141Sgr 20250203.8359 13.7c Observer: Tadashi Kojima (Tsumagoi,Gunma, Japan) Instruments:fl=300mm lens +Canon EOS6D digital camera

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[vsnet-alert 28041] TCP J04272195-2528038; possibly a new AM CVn star in outburst?
by Yusuke Tampo 02 Feb '25

02 Feb '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-alert 28040] 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-alert 28039] ASASSN-24hd is a ugwz star in outburst
by Berto Monard 27 Dec '24

27 Dec '24

Hello, Timeseries observations of ASASSN-24hd through a V filter were done on 24 and 25 Dec 2024 at CBA KKO. They covered the epochs JD 2460669.35-2460669.48 and JD 2460670.34-2460670.51 respectively. The LCs on both nights showed a clear periodic modulation (superhumps) in the shape of a saw tooth, a pattern that seems to occur with many outbursting ugwz stars seen over the years. The amplitude of the cyclic modulation during those nights were about .25V and .20V resp. and the mean brightness's were 12.79V and 12.92V. A period analysis using the PDM and GLS methods with Peranso 3.0 yielded a period of 0.583d +/- 0.003d on both nights, and considering the total observing baseline over the two nights a mean period of 0.580d +/- .0015d was derived. Earlier observations done on 19 Dec (mid-time JD 2460664.38) showed the object at a brightness of 12.06V but without any clear modulation. From the discovery data it can be concluded that the superhumps started between 8 and 12 days into the outburst. The large amplitude outburst, the considerable delay in the formation of superhumps, the LC pattern of the superhumps and the relative short periodicity of them ought to direct towards the ugwz status of ASASSN-24hd. Further observations are planned, weather allowing Berto Monard / CBA KKO Calitzdorp / South Africa

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[vsnet-alert 28038] 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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