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

[vsnet-alert 26269] LMC V1512 (Galactic DN) outburst (Sept. 6-17)
by Patrick Schmeer 24 Sep '21

24 Sep '21

LMC V1512 = "Nova" Mensae 1951 (UG) https://www.aavso.org/vsx/index.php?view=detail.top&oid=236395 A relatively rare outburst started on 2021 September 6 according to recent ASAS-SN Sky Patrol (Shappee et al. 2014ApJ...788...48S and Kochanek et al. 2017PASP..129j4502K) data: https://asas-sn.osu.edu/sky-patrol/coordinate/1348a779-1ab5-4f79-a58c-183ed… https://asas-sn.osu.edu/sky-patrol/coordinate/3e9155c6-4573-4917-9f6c-4c0bd… An apparent (short) rebrightening during the relatively fast decline (faster than that of a standard UGSU superoutburst) occurred on September 14. A previous outburst (= ASASSN-17lo) was recorded from 2017 August 29 to September 7 by the ASAS-SN Sky Patrol. Regards, Patrick

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[vsnet-alert 26268] CRTS J145921.8+354806 superoutburst
by Taichi Kato 24 Sep '21

24 Sep '21

CRTS J145921.8+354806 superoutburst YYYYMMDD(UT) mag observer 20210921.1771 15.703zr (Zwicky Transient Facility Lasair (Masci+ 2019)) 20210923.1584 15.411zg (Zwicky Transient Facility Lasair (Masci+ 2019)) 20210923.1746 15.803zr (Zwicky Transient Facility Lasair (Masci+ 2019))

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[vsnet-alert 26267] ASASSN-16og outburst
by Balaji Kumar 23 Sep '21

23 Sep '21

Our transient survey has detected an outburst of ASSASN-16og. First observed date: September 21.30969 Magnitude: 14.9 R ---------------- Balaji Golden Ears Observatory Transient Survey Maple Ridge, Canada

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[vsnet-alert 26266] V544 Her faded after double outburst and apparently rebrightened
by Taichi Kato 23 Sep '21

23 Sep '21

V544 Her faded after double outburst and apparently rebrightened YYYYMMDD(UT) mag observer 20210819.5030 <156c (Yutaka Maeda) 20210820.5016 <146c (Yutaka Maeda) 20210824.1742 15.119zr (Zwicky Transient Facility Lasair (Masci+ 2019)) 20210824.1938 14.913zg (Zwicky Transient Facility Lasair (Masci+ 2019)) 20210826.1947 15.308zr (Zwicky Transient Facility Lasair (Masci+ 2019)) 20210827.5030 151:c (Yutaka Maeda) 20210828.1876 15.252zg (Zwicky Transient Facility Lasair (Masci+ 2019)) 20210828.1877 15.252zg (Zwicky Transient Facility Lasair (Masci+ 2019)) 20210828.2713 15.354zr (Zwicky Transient Facility Lasair (Masci+ 2019)) 20210828.2715 15.354zr (Zwicky Transient Facility Lasair (Masci+ 2019)) 20210828.901 15.30C (Gary Poyner) 20210828.9028 15.22C (Masao Funada) 20210829.4567 157:cG (Yutaka Maeda) 20210830.8756 16.63C (Masao Funada) 20210831.2067 16.965zg (Zwicky Transient Facility Lasair (Masci+ 2019)) 20210831.2069 16.965zg (Zwicky Transient Facility Lasair (Masci+ 2019)) 20210831.4373 <164c (Yutaka Maeda) 20210831.5071 <166C (Masayuki Moriyama) 20210903.2085 17.666zr (Zwicky Transient Facility Lasair (Masci+ 2019)) 20210903.2086 17.666zr (Zwicky Transient Facility Lasair (Masci+ 2019)) 20210903.2667 17.995zg (Zwicky Transient Facility Lasair (Masci+ 2019)) 20210905.1945 15.505zr (Zwicky Transient Facility Lasair (Masci+ 2019)) 20210907.2273 15.298zr (Zwicky Transient Facility Lasair (Masci+ 2019)) 20210907.2275 15.298zr (Zwicky Transient Facility Lasair (Masci+ 2019)) 20210908.4314 155:c (Yutaka Maeda) 20210909.1497 15.498zr (Zwicky Transient Facility Lasair (Masci+ 2019)) 20210909.4912 150cG (Yutaka Maeda) 20210911.1659 15.415zg (Zwicky Transient Facility Lasair (Masci+ 2019)) 20210916.2071 18.551zg (Zwicky Transient Facility Lasair (Masci+ 2019)) 20210919.1506 17.415zg (Zwicky Transient Facility Lasair (Masci+ 2019)) 20210919.1749 17.114zr (Zwicky Transient Facility Lasair (Masci+ 2019))

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[vsnet-alert 26265] LL And: increase in the amplitude of superhumps
by Filipp Romanov 22 Sep '21

22 Sep '21

I reported (to the AAVSO and VSNET) my time-resolved V-band observations of LL And obtained remotely using 0.355-m f/6.2 Schmidt-Cassegrain telescope of Abbey Ridge Observatory (Canada). I clearly detected periodic superhumps with increasing amplitude: about 0.06 mag on September 20, about 0.10 mag on September 21 and about 0.25 mag on September 22. With best regards, Filipp.

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[vsnet-alert 26264] LL And: stage A superhumps and mass ratio
by Taichi Kato 22 Sep '21

22 Sep '21

LL And: stage A superhumps and mass ratio Kyoto U. team, Crimean Astrophys. Obs. team, Itoh-san, Alexandra Zubareva, Tonny Vanmunster, Tamas Tordai, Filipp Romanov and Kiyota-san have reported observations. The object started to show well-detectable superhumps since Sep. 20. The current period (stage A) is 0.0579(1) d. This period corresponds to q=0.143(5). This value is consistent with the result in https://ui.adsabs.harvard.edu/abs/2004PASJ...56S.135K/abstract This object is likely an SU UMa star (rather than a WZ Sge star) as judged from the mass ratio despite the very long supercycle. The lack of strong early superhumps appears to be consistent with this classification.

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[vsnet-alert 26263] ASASSN-19ax superhump period
by Taichi Kato 22 Sep '21

22 Sep '21

ASASSN-19ax superhump period Itoh-san, Kiyota-san, Tonny Vanmunster and Tamas Tordai have reported observations. The superhump period is established to be 0.10012(2) d. There is currently no period variation.

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[vsnet-alert 26262] LL And showing regular superhumps
by tonny.vanmunster＠gmail.com 22 Sep '21

22 Sep '21

Dear colleagues, I obtained another LL And time series last night (2021, Sep 20/21) at CBA Extremadura Observatory in Spain, using a 0.40-m f/5.1 telescope and SX-46 CCD camera under clear skies. Looking at the resulting light curve, it seems that early superhumps have now been replaced by regular superhumps with an amplitude of 0.15 mag. The object was at mag CV = 13.9 on Sep 21st. 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

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[vsnet-alert 26261] TCP J20115874-1922459: likely a dwarf nova outburst (mag. 15, in Capricornus)
by Patrick Schmeer 22 Sep '21

22 Sep '21

TCP J20115874-1922459 = BraTS-SON-T2-032 (UG:) https://www.aavso.org/vsx/index.php?view=detail.top&oid=2224741 Complete 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/eaad0624-e1cc-4b94-81ea-82a5d… Outburst amplitude 7 magnitudes. Already in outburst (orange mag. ~15.4) on 2021 September 20.358 UT according to ATLAS data. Time-resolved photometry is encouraged. Clear skies, Patrick ------- References: All-Sky Automated Survey for Supernovae (ASAS-SN) Sky Patrol: - Shappee et al., 2014ApJ...788...48S - Kochanek et al., 2017PASP..129j4502K Asteroid Terrestrial-impact Last Alert System (ATLAS): - Tonry et al., 2018PASP..130f4505T

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[vsnet-alert 26260] ASASSN-19ax: new long period SU UMa-type dwarf nova
by tonny.vanmunster＠gmail.com 18 Sep '21

18 Sep '21

Dear colleagues, I have just finished analysing my unfiltered observations of ASASSN-19ax, obtained on 2021, September 17/18 at CBA Belgium Observatory (0.40-m f/10.0 telescope, QHY-268M CMOS, clear then clouds) and at CBA Extremadura Observatory (0.40-m f/5.1 telescope, SX-46 CCD, clear then clouds). The combined lightcurve covers a time span of 7.2h and clearly shows the presence of superhumps with an amplitude of 0.26 mag, establishing ASASSN-19ax 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 0.1015 +/- 0.0024d, well above the period gap (as suspected by Taichi Kato in vsnet-alert 26256). The object was at mag CV = 13.5 on Sep 18th. 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

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