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

[vsnet-alert 27953] X Ser in outburst
by Robert J. Modic 31 Aug '23

31 Aug '23

CCD Observations Object YYYYMMDD(UT) Mag Obs Chart Remarks SERX 20230830.635 15.62V MRV Henden MPO61; Err 0.04; Outburst Instruments: RCOS 24" w/FLI PL1603, AAVSONet (MPO61) Observer: Robert J. Modic (MRV)

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[vsnet-alert 27948] Swift J1727.8-1613: black-hole binary and V404 Cyg-like object ?
by Mariko Kimura 30 Aug '23

30 Aug '23

Swift J1727.8-1613: black-hole binary and V404 Cyg-like object ? Swift and MAXI detected an outburst in Swift J1727.8-1613. This is a candidate for a black-hole binary and possibly similar to V404 Cyg, a unique object known as a source of rapid variability. A few seconds variability was already found in X-rays. The most violent variability would be ~2 mag in several tens of min. This is very bright. Currently, ~13 mag. The position is (RA)17:27:46 (DEC)-16:12:53 reported by Swift. Follow-up observations are strongly encouraged. https://www.astronomerstelegram.org/?read=16205 https://www.astronomerstelegram.org/?read=16208 - Mariko Kimura at Kanazawa Univ. in Japan

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[vsnet-alert 27950] Re: SwiftJ1727.8-1613
by Taichi Kato 26 Aug '23

26 Aug '23

Re: SwiftJ1727.8-1613 Itoh-san reported time-resolved photometry (as TCP J17274332-1612188). Strong short-term variations comparable to V404 Cyg (more than 0.1 mag) were not detected.

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[vsnet-alert 27949] MASTER OT J183342.09+654019.1 superoutburst
by Taichi Kato 26 Aug '23

26 Aug '23

MASTER OT J183342.09+654019.1 superoutburst Superhumps of this object were observed in 2021 Apr., but not so well. YYYYMMDD(UT) mag observer 20230803.2927 17.662g (ASAS-SN Sky Patrol Photom. DB (Hart+2023; Shappee+2014)) 20230805.3107 17.534g (ASAS-SN Sky Patrol Photom. DB (Hart+2023; Shappee+2014)) 20230814.4402 17.555g (ASAS-SN Sky Patrol Photom. DB (Hart+2023; Shappee+2014)) 20230822.4005 15.150g (ASAS-SN Sky Patrol Photom. DB (Hart+2023; Shappee+2014)) (forwarded message) === From: <andrew_simon(a)univ.kiev.ua> Date: Fri, 25 Aug 2023 22:43:27 +0300 Dear Dr. Taichi Kato, According to my observations in the Lisnyky observational station during the last two nights it looks like the object Gaia19cuu now in superoutburst. From the observations superhumps can be easily detected on the images attached to this letter. Data from the Gaia shows previous outbursts with the amplitude of 4-5 magnitudes (https://gsaweb.ast.cam.ac.uk/alerts/alert/Gaia19cuu/) Also data from Gaia Followup for 7 Jul 2019 submitted by Liam Hardy shows superhumps, due to these data I started to follow this object. ( https://gsaweb.ast.cam.ac.uk/alerts/alert/Gaia19cuu/followup) ZTF also detected multiple outbursts in the light curve as well as current outburst. https://lasair-ztf.lsst.ac.uk/objects/ZTF18aatluwz/ After analysing the data I found 0.068d period for 2023-08-23 and 0.077d period for 2023-08-24. But due to the relatively short duration of observations these determinations can be not precise. Obtained data relatively to the comp.star I also attached to this letter. This night it is cloudy in Kyiv so I have no possibility to continue observations. But I hope that the object will appear to be interesting for observations over the world. Best regards, Andrew Simon.

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[vsnet-alert 27947] Re: FZ Cet (UGSU) outburst
by Taichi Kato 21 Aug '23

21 Aug '23

> The UGSU-type dwarf nova FZ Cet is in outburst according to NMW survey > photometry (135mm f/2.0 lens + unfiltered STL-11000 CCD): Please pay attention not to post a new message as a reply to an old, unrelated message. See how your posting looks like: http://ooruri.kusastro.kyoto-u.ac.jp/mailman3/hyperkitty/list/vsnet-alert@o…

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[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 27945] Optical high state of Blazar 1ES 1959+650
by Stefan Karge 15 Aug '23

15 Aug '23

Blazar 1ES 1959+650 in optical high state object date (UTC) mag comment -------------------------------------------------- 1959+650 20230717.874 14.17V active (1) 1959+650 20230805.109 14.06V active (1) 1959+650 20230812.952 13.99V active (1) -------------------------------------------------- The optical high state corresponds well with strong X-ray activity detected by Swift-XRT (see Atel #16186). -------------------------------------------------- (1) 30cm-Refl. + CCD + V-Johnson (remote) Stefan Karge (SKA) http://quasar.square7.ch/fqm/1959+650.html _______________________________________________

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[vsnet-alert 27944] TCP J16420534+8156125 ordinary superhumps
by Taichi Kato 12 Aug '23

12 Aug '23

TCP J16420534+8156125 ordinary superhumps The most recent observations by Itoh-san on Aug. 12 showed ordinary superhumps.

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[vsnet-alert 27927] TCP J16420534+8156125 bright likely dwarf nova
by Taichi Kato 09 Aug '23

09 Aug '23

TCP J16420534+8156125 bright likely dwarf nova http://cbat.eps.harvard.edu/unconf/followups/J16420534+8156125.html 164209.215 +815556.26 (2000.0) Gaia_DR2_1710719047756794368 plx=1.700(0.682) dismod=8.8 pmra=-13.473(1.951) pmdec=25.647(2.137) G=20.587 BP=20.469 RP=20.125 164209.212 +815556.28 (2000.0) Gaia_EDR3_1710719047756794368 plx=1.896(0.572) dismod=8.6 pmra=-13.299(0.746) pmdec=25.917(0.841) G=20.494 BP=20.613 RP=20.253

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[vsnet-alert 27942] TY PsA superoutburst
by Taichi Kato 09 Aug '23

09 Aug '23

TY PsA superoutburst YYYYMMDD(UT) mag observer 20230804.4195 15.543zr (ZTF Alert DC mag (Masci+ 2019)) 20230805.4013 15.690g (ASAS-SN Sky Patrol Photom. DB (Hart+2023; Shappee+2014)) 20230805.4326 15.663zg (ZTF Alert DC mag (Masci+ 2019)) 20230805.8474 15.230g (ASAS-SN Sky Patrol Photom. DB (Hart+2023; Shappee+2014)) 20230806.3172 11.890g (ASAS-SN Sky Patrol Photom. DB (Hart+2023; Shappee+2014)) 20230807.526 110 (Rod Stubbings) 20230807.8910 11.626g (ASAS-SN Sky Patrol Photom. DB (Hart+2023; Shappee+2014)) 20230808.546 110 (Rod Stubbings)

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vsnet-alert August 2023