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

[vsnet-alert 26213] SDSS J172102.48+273301.2 (AM CVn) dip after short superoutburst
by Taichi Kato 07 Sep '21

07 Sep '21

SDSS J172102.48+273301.2 (AM CVn) dip after short superoutburst YYYYMMDD(UT) mag observer 20210831.2081 19.372zg (Zwicky Transient Facility Lasair (Masci+ 2019)) 20210903.2167 16.261zr (Zwicky Transient Facility Lasair (Masci+ 2019)) 20210905.2264 16.557zr (Zwicky Transient Facility Lasair (Masci+ 2019)) 20210905.2765 16.267zg (Zwicky Transient Facility Lasair (Masci+ 2019)) 20210907.1802 18.617zg (Zwicky Transient Facility Lasair (Masci+ 2019))

1 0

[vsnet-alert 26212] MGAB-V258 possible superoutburst
by Taichi Kato 07 Sep '21

07 Sep '21

MGAB-V258 possible superoutburst YYYYMMDD(UT) mag observer 20210823.4701 19.445zg (Zwicky Transient Facility Lasair (Masci+ 2019)) 20210825.4670 20.335zr (Zwicky Transient Facility Lasair (Masci+ 2019)) 20210827.4496 20.419zg (Zwicky Transient Facility Lasair (Masci+ 2019)) 20210827.4498 20.419zg (Zwicky Transient Facility Lasair (Masci+ 2019)) 20210902.4561 17.734zg (Zwicky Transient Facility Lasair (Masci+ 2019)) 20210902.4838 17.537zr (Zwicky Transient Facility Lasair (Masci+ 2019)) 20210904.4502 17.657zg (Zwicky Transient Facility Lasair (Masci+ 2019)) 20210904.4504 17.657zg (Zwicky Transient Facility Lasair (Masci+ 2019))

1 0

[vsnet-alert 26211] ASASSN-18hr likely superoutburst
by Taichi Kato 07 Sep '21

07 Sep '21

ASASSN-18hr likely superoutburst Suspected ER UMa star. YYYYMMDD(UT) mag observer 20210821.2250 18.820zr (Zwicky Transient Facility Lasair (Masci+ 2019)) 20210821.3013 18.577zg (Zwicky Transient Facility Lasair (Masci+ 2019)) 20210824.2447 16.184zg (Zwicky Transient Facility Lasair (Masci+ 2019)) 20210824.3044 16.310zr (Zwicky Transient Facility Lasair (Masci+ 2019)) 20210826.2604 16.232zr (Zwicky Transient Facility Lasair (Masci+ 2019)) 20210826.2979 16.199zg (Zwicky Transient Facility Lasair (Masci+ 2019)) 20210828.2131 16.321zg (Zwicky Transient Facility Lasair (Masci+ 2019)) 20210828.2630 16.681zr (Zwicky Transient Facility Lasair (Masci+ 2019)) 20210901.2677 16.462zg (Zwicky Transient Facility Lasair (Masci+ 2019)) 20210903.2863 16.769zg (Zwicky Transient Facility Lasair (Masci+ 2019)) 20210905.2440 17.136zr (Zwicky Transient Facility Lasair (Masci+ 2019)) 20210905.2575 16.901zg (Zwicky Transient Facility Lasair (Masci+ 2019))

1 0

[vsnet-alert 26210] Re: ASASSN-21nv: at least four rebrightenings
by Taichi Kato 07 Sep '21

07 Sep '21

Re: ASASSN-21nv: at least four rebrightenings > The (super?)outburst started on 2021 July 27. A rapid fading began on August 23. > Short rebrightenings were recorded on August 27 and 30, and on September 2 and 4. > (according to ZTF, ATLAS and ASAS-SN data) Look like a short rebrightening and a long one (according to ZTF Lasair). ASAS-SN data are noisy (fainter thans around positive detections).

1 0

[vsnet-alert 26209] ASASSN-21nv: at least four rebrightenings
by Patrick Schmeer 06 Sep '21

06 Sep '21

ASASSN-21nv (UGWZ:) https://www.aavso.org/vsx/index.php?view=detail.top&oid=2223860 ZTF light curve, data, and images (via Lasair): https://lasair.roe.ac.uk/object/ZTF21abouwjj/ Recent ASAS-SN Sky Patrol light curve and data: https://asas-sn.osu.edu/sky-patrol/coordinate/dc7c9a1a-df53-4dd2-8866-99e32… The (super?)outburst started on 2021 July 27. A rapid fading began on August 23. Short rebrightenings were recorded on August 27 and 30, and on September 2 and 4. (according to ZTF, ATLAS and ASAS-SN data) Time-resolved photometry was performed by Tonny Vanmunster (VMT) during six observing sessions (July 30 - Aug. 3 and Aug. 10 UT); no superhumps were detected: https://app.aavso.org/webobs/results/?star=ASASSN-21nv Follow-up observations are 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 Lasair: - Smith et al., 2019RNAAS...3...26S Zwicky Transient Facility (ZTF): - Masci et al., 2019PASP..131a8003M

1 0

[vsnet-alert 26207] MASTER OT J052622.61+734629.7: new SU UMa-type dwarf nova
by Taichi Kato 06 Sep '21

06 Sep '21

MASTER OT J052622.61+734629.7: new SU UMa-type dwarf nova Tamas Tordai and Josch Hambsch have reported observations. The object shows superhumps with a period of 0.06549(4) d and an amplitude of 0.28 mag.

2 1

[vsnet-alert 26206] ASASSN-V J205543.90+240033.5: true period
by Taichi Kato 05 Sep '21

05 Sep '21

ASASSN-V J205543.90+240033.5 (AR Sco-like object): true period After an analysis of the ZTF data, I reached a conclusion that the true period is 0.523490(1) d. All the data can be well expressed by this period and the profile is sinusoidal (reflection type). The 10.803 d period I reported appears to be its alias. The initially reported 0.2-d period was caused by the incomplete phase coverage. Now this object looks even more similar to AR Sco (Porb=0.14853528 d, spin=1.95 min). I will publish a corrected report shortly. Special thanks to Elena Pavlenko for pointing out the likely error in the period.

1 0

[vsnet-alert 26205] ASASSN-21qi: new SU UMa-type dwarf nova
by Taichi Kato 05 Sep '21

05 Sep '21

ASASSN-21qi: new SU UMa-type dwarf nova Berto Monard has reported observations. The object has been showing superhump (amplitude 0.18 mag) since Aug. 26. The period is 0.06141(2) d allowing aliases (alias still not selected due to the limited coverage).

1 0

[vsnet-alert 26204] TCP J19092450+3041330: new SU UMa-type dwarf nova
by tonny.vanmunster＠gmail.com 05 Sep '21

05 Sep '21

Dear colleagues, I have just finished analysing my unfiltered observations of TCP J19092450+3041330, obtained on 2021, September 04/05 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 skies). Combining both observation sets, regular superhumps with an amplitude of 0.40 mag are clearly visible in the resulting light curve, establishing TCP J19092450+3041330 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 0.0680 +/- 0.0002d. The object was at mag CV = 16.1 on Sep 05th. 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

1 0

[vsnet-alert 26198] SDSS J172102.48+273301.2: AM CVn object with double superoutburst
by Naoto Kojiguchi 05 Sep '21

05 Sep '21

SDSS J172102.48+273301.2: AM CVn object with double superoutburst Taguchi-san has reported the latest outburst of this object detected by ZTF alert. This object will soon show a second superoutburst. SC ~ 9.3 yr. Time-resolved photometry is required. YYYYMMDD(UT) mag observer comment 20210825.323 <16.677g ASN 20210826.196 15.852zr ZLR Start of outburst 20210826.217 15.659g ASN 20210827.277 16.078o ATF 20210827.319 15.813g ASN 20210828.195 15.757zg ZLR 20210828.211 15.764g ASN 20210828.258 16.124zr ZLR 20210829.044 15.935g ASN 20210829.275 16.140cy ATF 20210830.751 <16.748g ASN Start of dip 20210831.208 19.372zg ZLR 20210831.333 19.748o ATF ATF (ATLAS Forced Photometry (Tonry et al. 2018)) ASN (ASAS-SN survey (Shappee+ 2014; Kochanek+ 2017)) ZLR (Zwicky Transient Facility Lasair (Masci+ 2019))

2 1