February 2023 - vsnet-alert - ooruri.kusastro.kyoto-u.ac.jp

[vsnet-alert 27039] GX Cas (UGSU) outburst
by Kirill Sokolovsky 20 Aug '23

20 Aug '23

The UGSU-type dwarf nova GX Cas is in outburst according to NMW survey photometry (135mm f/2.0 lens + unfiltered ST-8300M CCD): 2022-11-13.7397 2459897.2397 13.4 CV AAVSO observer KLO reports visual observation of this outburst: 2022-11-12.9520 2459896.4520 13.6 Vis. ASAS-SN photometry (latest observation is quiescence on 2022-11-12.165): https://asas-sn.osu.edu/sky-patrol/coordinate/7c8f8333-01a3-49aa-ba14-08b07… VSX record for GX Cas https://www.aavso.org/vsx/index.php?view=detail.top&oid=6537 Best wishes, Kirill Sokolovsky, Stanislav Korotkiy, Olga Smolyankina, Anna Prokudina, Sergei Ostapenko

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[vsnet-alert 27461] ASASSN-15cu possible superoutburst
by Taichi Kato 28 Feb '23

28 Feb '23

ASASSN-15cu possible superoutburst Likely eclipsing. YYYYMMDD(UT) mag observer 20230213.8500 19.292o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230213.8577 19.458o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230219.0751 19.097c (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230219.0787 19.220c (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230221.8495 16.046o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230221.8527 16.037o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230221.8595 16.083o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230221.8704 16.070o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230223.0719 15.488c (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230223.0755 15.516c (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230223.0809 15.535c (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230223.0909 15.613c (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230225.3046 15.330o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230225.3077 15.313o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230225.3128 15.364o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230225.3267 15.575o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230227.0660 15.529o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230227.0692 15.593o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230227.0746 15.700o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230227.0856 16.834o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505))

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[vsnet-alert 27460] SSSJ090619.2-275831
by Taichi Kato 28 Feb '23

28 Feb '23

SSSJ090619.2-275831 likely superoutburst (Likely SU UMa/ER UMa star) YYYYMMDD(UT) mag observer 20230221.6214 157C (Masayuki Moriyama) 20230224.6354 <160C (Masayuki Moriyama) 20230226.6103 16.01C (Masayuki Moriyama)

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[vsnet-alert 27459] SX LMi rebrightening
by Taichi Kato 28 Feb '23

28 Feb '23

SX LMi rebrightening YYYYMMDD(UT) mag observer 20230224.6904 <155c (Yutaka Maeda) 20230224.985 <146 (Gary Poyner) 20230225.8917 <142 (Eddy Muyllaert) 20230225.982 <146 (Gary Poyner) 20230226.6559 153:c (Yutaka Maeda) 20230226.8161 152C (Masayuki Moriyama)

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[vsnet-alert 27458] ASASSN-23ba: updated period of early superhumps
by Taichi Kato 27 Feb '23

27 Feb '23

ASASSN-23ba: updated period of early superhumps The data are from Berto Monard, Peter Starr, Josch Hambsch and Itoh-san. The period is 0.05662(1) d.

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[vsnet-alert 27457] ASASSN-23aw: new SU UMa star
by Taichi Kato 27 Feb '23

27 Feb '23

ASASSN-23aw: new SU UMa star Using observations by Josch Hambsch, superhumps have developed since Feb. 23. The period is 0.0520(1) or 0.0549(1) d (rather difficult to determine due to the low sampling rate).

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[vsnet-alert 27456] ASASSN-23ax: rebrightening
by Taichi Kato 27 Feb '23

27 Feb '23

ASASSN-23ax: rebrightening Josch Hambsch detected a rebrightening on Feb. 26 after a dip of 2-3 d.

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[vsnet-alert 27455] Re: MASTER OT J055845.55+391533.4: new SU UMa-type dwarf nova
by Taichi Kato 25 Feb '23

25 Feb '23

Re: MASTER OT J055845.55+391533.4: new SU UMa-type dwarf nova > The resulting light curve clearly shows the presence of regular superhumps > (4 in total) with an amplitude of 0.20 mag, establishing MASTER OT > J055845.55+391533.4 as a new SU UMa-type dwarf nova. The object is unusual in that it almost regularly showed a deep dip during past outbursts. There were sometimes variations like oscillations after the dip, and the overall behavior resembles a double superoutburst. 2018 Apr., 2019 Mar.-Apr., 2020 May, 2021 Jan.-Feb., 2021 Sep. all showed this feature. There was, however, no fading tail looking like an AM CVn star. The number of normal outbursts was smaller than that of superoutbursts. Please continue observing, since a dip is expected within a week. Recording variation of superhumps during the entire course of a superoutburst is very important to see what is happening.

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[vsnet-alert 27454] MASTER OT J055845.55+391533.4: new SU UMa-type dwarf nova
by tonny.vanmunster＠gmail.com 25 Feb '23

25 Feb '23

Dear colleagues, I have just finished analysing my unfiltered CCD observations of MASTER OT J055845.55+391533.4 obtained on 2023, Feb 22/23 at CBA Extremadura Observatory (Spain) using a 0.40-m f/5.1 telescope and SX-46 CCD camera under relatively clear skies. The resulting light curve clearly shows the presence of regular superhumps (4 in total) with an amplitude of 0.20 mag, establishing MASTER OT J055845.55+391533.4 as a new SU UMa-type dwarf nova. A period analysis, using the ANOVA, Generalized-Lomb-Scargle, PDM and Conditional Entropy methods (Peranso 3.0) yields a combined superhump period of 0.0553 +/- 0.0004d. The object was at mag CV = 14.4 on Feb 23rd. 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> http://www.cbabelgium.com PERANSO: The Light Curve and Period Analysis Software http://www.peranso.com

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[vsnet-alert 27453] MASTER OT J055845.55+391533.4 superhumps?
by Taichi Kato 25 Feb '23

25 Feb '23

MASTER OT J055845.55+391533.4 superhumps? Kiyota-san reported observations. The data appear consistent with a longer superhump period of a hydrogen-rich system. The data, however, were not enough and more observations are needed (the outburst behavior is unusual for ar ordinary SU UMa star).

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vsnet-alert February 2023