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

[vsnet-alert 27777] ASASSN-22ak period
by Taichi Kato 25 May '23

25 May '23

ASASSN-22ak period Josch Hambsch has reported further observations. Thanks to the recent high-cadence data, the period has been established. The object brightened a bit on May 21 and the period since then has been 0.04292(2) d. Based on this alias selection, the period from the entire data is 0.043032(4) d. The profile still never appeared to be typical superhump-like. It has been fast rising and slower fading, as in early superhumps. The amplitude is 0.04 mag. The observations appear to confirm the classification of the object as being below the period minimum (EI Psc star).

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[vsnet-alert 27776] Gaia DR3 4538714906329565952 = ZTF23aaladoy outburst
by Taichi Kato 25 May '23

25 May '23

Gaia DR3 4538714906329565952 = ZTF23aaladoy outburst Fading too rapidly for a superoutburst? YYYYMMDD(UT) mag observer 20230521.5006 15.905o (ATLAS Forced Photometry (Tonry+2018; Shingles+2021)) 20230521.5024 15.928o (ATLAS Forced Photometry (Tonry+2018; Shingles+2021)) 20230521.5063 15.932o (ATLAS Forced Photometry (Tonry+2018; Shingles+2021)) 20230521.5122 15.924o (ATLAS Forced Photometry (Tonry+2018; Shingles+2021)) 20230523.6066 16.246o (ATLAS Forced Photometry (Tonry+2018; Shingles+2021)) 20230523.6098 16.270o (ATLAS Forced Photometry (Tonry+2018; Shingles+2021)) 20230523.6130 16.303o (ATLAS Forced Photometry (Tonry+2018; Shingles+2021)) 20230523.7678 165V (Masayuki Moriyama) 20230523.7688 16.43C (Masayuki Moriyama)

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[vsnet-alert 27775] ASASSN-13bs outburst
by Taichi Kato 25 May '23

25 May '23

ASASSN-13bs outburst Subtype unknown. Rather strange behavior in the past. YYYYMMDD(UT) mag observer 20230513.6041 <167C (Masayuki Moriyama) 20230514.599 175C (Mitsutaka Hiraga) 20230514.7266 <163C (Masayuki Moriyama) 20230514.7332 <149c (Yutaka Maeda) 20230515.6956 <145c (Yutaka Maeda) 20230519.7000 <162c (Yutaka Maeda) 20230520.576 175C (Mitsutaka Hiraga) 20230523.7797 144C (Masayuki Moriyama)

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[vsnet-alert 27774] CH Her likely superoutburst
by Taichi Kato 25 May '23

25 May '23

CH Her likely superoutburst Time-resolved photometry is strongly encouraged. Not done before. (ZTF and ATLAS data suggest an SU UMa star, as previously reported) YYYYMMDD(UT) mag observer 20230515.597 <175C (Mitsutaka Hiraga) 20230515.6874 <151c (Yutaka Maeda) 20230516.5026 16.842g (ASAS-SN Sky Patrol Photom. DB (Hart+2023; Shappee+2014)) 20230516.6808 <144c (Yutaka Maeda) 20230519.6916 <141c (Yutaka Maeda) 20230521.4021 14.456g (ASAS-SN Sky Patrol Photom. DB (Hart+2023; Shappee+2014)) 20230522.5081 14.468g (ASAS-SN Sky Patrol Photom. DB (Hart+2023; Shappee+2014)) 20230523.7832 149C (Masayuki Moriyama)

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[vsnet-alert 27773] Gaia DR3 2893005857946801152 = ASASSN-23dr: most likely WZ Sge star
by Taichi Kato 24 May '23

24 May '23

Gaia DR3 2893005857946801152 = ASASSN-23dr: most likely WZ Sge star Josch Hambsch has reported further observations. There was an apparent superhump on May 22-23. As judged from the outburst light curve, the object probably entered the phase of ordinary superhumps (but there was a gap in the data). The initial rapid decay and the waiting time suggest a WZ Sge star.

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[vsnet-alert 27772] V592 Her superoutburst, recent data
by Taichi Kato 24 May '23

24 May '23

V592 Her superoutburst, recent data Apparently in SU UMa mode (superoutburst in 2021 Dec.). Quiescence has become brighter (ZTF data). Itoh-san already detected superhump-like modulations. YYYYMMDD(UT) mag observer 20230518.1626 <18.162g (ASAS-SN Sky Patrol Photom. DB (Hart+2023; Shappee+2014)) 20230518.4078 <18.399g (ASAS-SN Sky Patrol Photom. DB (Hart+2023; Shappee+2014)) 20230518.9549 <142 (Eddy Muyllaert) 20230519.6030 <144c (Yutaka Maeda) 20230521.022 <153 (Gary Poyner) 20230521.1861 15.227g (ASAS-SN Sky Patrol Photom. DB (Hart+2023; Shappee+2014)) 20230521.4146 16.026o (ATLAS Forced Photometry (Tonry+2018; Shingles+2021)) 20230521.4209 15.989o (ATLAS Forced Photometry (Tonry+2018; Shingles+2021)) 20230521.4232 16.011o (ATLAS Forced Photometry (Tonry+2018; Shingles+2021)) 20230521.4469 16.005o (ATLAS Forced Photometry (Tonry+2018; Shingles+2021)) 20230521.4696 15.395g (ASAS-SN Sky Patrol Photom. DB (Hart+2023; Shappee+2014)) 20230522.008 <149 (Gary Poyner) 20230522.4398 16.024g (ASAS-SN Sky Patrol Photom. DB (Hart+2023; Shappee+2014)) 20230522.989 15.10 (Pavol A. Dubovsky) 20230523.026 15.17 (Pavol A. Dubovsky) 20230523.1519 15.120g (ASAS-SN Sky Patrol Photom. DB (Hart+2023; Shappee+2014)) 20230523.5219 15.609o (ATLAS Forced Photometry (Tonry+2018; Shingles+2021)) 20230523.5255 15.620o (ATLAS Forced Photometry (Tonry+2018; Shingles+2021)) 20230523.5333 15.588o (ATLAS Forced Photometry (Tonry+2018; Shingles+2021)) 20230523.6072 150:c (Yutaka Maeda)

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[vsnet-alert 27770] V592 Her in outburst
by Pavol A. Dubovsky 23 May '23

23 May '23

HERV592 20230522.989 15.10 DPV OUTBURST -- Pavol A. Dubovsky Vihorlat Observatory Humenne SLOVAKIA http://var.kozmos.sk

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[vsnet-alert 27769] ZTF23aajjayv still bright
by Taichi Kato 23 May '23

23 May '23

ZTF23aajjayv still bright The light curve suggests a superoutburst. YYYYMMDD(UT) mag observer 20230512.0661 <16.962g (ASAS-SN survey (Shappee+2014; Kochanek+2017)) 20230512.0673 <17.048g (ASAS-SN survey (Shappee+2014; Kochanek+2017)) 20230512.0686 16.874g (ASAS-SN survey (Shappee+2014; Kochanek+2017)) 20230512.2494 <15.386g (ASAS-SN survey (Shappee+2014; Kochanek+2017)) 20230512.2507 <15.026g (ASAS-SN survey (Shappee+2014; Kochanek+2017)) 20230512.2519 <14.876g (ASAS-SN survey (Shappee+2014; Kochanek+2017)) 20230512.4247 <17.254g (ASAS-SN survey (Shappee+2014; Kochanek+2017)) 20230512.4260 16.854g (ASAS-SN survey (Shappee+2014; Kochanek+2017)) 20230512.4273 16.891g (ASAS-SN survey (Shappee+2014; Kochanek+2017)) 20230513.3099 15.520zr (ZTF Alert DC mag (Masci+ 2019)) 20230513.3544 15.942zg (ZTF Alert DC mag (Masci+ 2019)) 20230513.3678 15.602g (ASAS-SN survey (Shappee+2014; Kochanek+2017)) 20230513.3691 15.647g (ASAS-SN survey (Shappee+2014; Kochanek+2017)) 20230513.3703 15.463g (ASAS-SN survey (Shappee+2014; Kochanek+2017)) 20230514.2359 14.480o (ATLAS Forced Photometry (Tonry+2018; Shingles+2021)) 20230514.2438 14.520o (ATLAS Forced Photometry (Tonry+2018; Shingles+2021)) 20230514.2479 14.494o (ATLAS Forced Photometry (Tonry+2018; Shingles+2021)) 20230514.3689 14.031g (ASAS-SN survey (Shappee+2014; Kochanek+2017)) 20230514.3701 14.026g (ASAS-SN survey (Shappee+2014; Kochanek+2017)) 20230514.3714 14.040g (ASAS-SN survey (Shappee+2014; Kochanek+2017)) 20230515.2651 14.217zg (ZTF Alert DC mag (Masci+ 2019)) 20230515.3262 14.161g (ASAS-SN survey (Shappee+2014; Kochanek+2017)) 20230515.3274 14.166g (ASAS-SN survey (Shappee+2014; Kochanek+2017)) 20230515.3287 14.186g (ASAS-SN survey (Shappee+2014; Kochanek+2017)) 20230515.9732 14.266g (ASAS-SN survey (Shappee+2014; Kochanek+2017)) 20230515.9745 14.256g (ASAS-SN survey (Shappee+2014; Kochanek+2017)) 20230515.9757 14.302g (ASAS-SN survey (Shappee+2014; Kochanek+2017)) 20230516.3228 14.295g (ASAS-SN survey (Shappee+2014; Kochanek+2017)) 20230516.3240 14.314g (ASAS-SN survey (Shappee+2014; Kochanek+2017)) 20230516.3253 14.279g (ASAS-SN survey (Shappee+2014; Kochanek+2017)) 20230517.2755 14.455zr (ZTF Alert DC mag (Masci+ 2019)) 20230517.3008 14.431zg (ZTF Alert DC mag (Masci+ 2019)) 20230519.2269 14.588zr (ZTF Alert DC mag (Masci+ 2019)) 20230519.3191 14.640zg (ZTF Alert DC mag (Masci+ 2019)) 20230520.6197 15.15C (Masayuki Moriyama) 20230521.5852 152C (Masayuki Moriyama)

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[vsnet-alert 27768] ASASSN-18dh: most likely superoutburst (AM CVn?)
by Taichi Kato 22 May '23

22 May '23

ASASSN-18dh: most likely superoutburst (AM CVn?) 2021 outburst followed by multiple rebrightenings + fading tail (ATLAS+ZTF). Less clear but similar in 2018. Resembles an AM CVn star. YYYYMMDD(UT) mag observer 20230506.2587 16.138g (ASAS-SN Sky Patrol Photom. DB (Hart+2023; Shappee+2014)) 20230508.3587 <17.350g (ASAS-SN Sky Patrol Photom. DB (Hart+2023; Shappee+2014)) 20230510.3436 <17.899g (ASAS-SN Sky Patrol Photom. DB (Hart+2023; Shappee+2014)) 20230510.9126 <16.261g (ASAS-SN Sky Patrol Photom. DB (Hart+2023; Shappee+2014)) 20230511.1877 <16.957g (ASAS-SN Sky Patrol Photom. DB (Hart+2023; Shappee+2014)) 20230512.3366 16.112g (ASAS-SN Sky Patrol Photom. DB (Hart+2023; Shappee+2014)) 20230514.1866 <17.921g (ASAS-SN Sky Patrol Photom. DB (Hart+2023; Shappee+2014)) 20230517.2269 15.779g (ASAS-SN Sky Patrol Photom. DB (Hart+2023; Shappee+2014)) 20230518.7854 16.204c (ATLAS Forced Photometry (Tonry+2018; Shingles+2021)) 20230518.7886 16.252c (ATLAS Forced Photometry (Tonry+2018; Shingles+2021)) 20230518.7942 16.247c (ATLAS Forced Photometry (Tonry+2018; Shingles+2021)) 20230518.8043 16.208c (ATLAS Forced Photometry (Tonry+2018; Shingles+2021)) 20230519.2205 16.119g (ASAS-SN Sky Patrol Photom. DB (Hart+2023; Shappee+2014))

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[vsnet-alert 27767] Gaia DR3 5931782154434729600 = Gaia23bt: likely RCB star fading
by Taichi Kato 21 May '23

21 May '23

Gaia DR3 5931782154434729600 = Gaia23bt: likely RCB star fading http://gsaweb.ast.cam.ac.uk/alerts/alert/Gaia23btd/ Non-red and luminious object. Consistent with RCB. 2MASS 161615.906 -544445.35 (2000.0) 12.495 12.134 11.774 161615.9 -544445 (2000.0) Gaia_DR3_5931782154434729600 RS (score=0.01) 161615.931 -544445.47 (2000.0) Gaia_DR2_5931782154434729600 plx=0.015(0.032) dismod=19.2 pmra=-2.920(0.052) pmdec=-2.724(0.041) G=14.549 BP=15.236 RP=13.707 161615.930 -544445.47 (2000.0) Gaia_EDR3_5931782154434729600 plx=0.021(0.024) dismod=18.4 pmra=-2.885(0.028) pmdec=-2.745(0.021) G=14.538 BP=15.214 RP=13.699

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vsnet-alert May 2023