June 2022 - vsnet-newvar - ooruri.kusastro.kyoto-u.ac.jp

[vsnet-newvar 9373] Re: ASASSN-18su
by Taichi Kato 29 Jun '22

29 Jun '22

Re: ASASSN-18su Superhumps were already detected during the 2018 superoutburst by Berto Monard. Superhumps appeared on 2018 Aug. 25. Due to the short visibility, the period was not determined.

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[vsnet-newvar 9371] ASASSN-18su (super?)outburst (since June 24)
by Patrick Schmeer 29 Jun '22

29 Jun '22

ASASSN-18su (UG) https://www.aavso.org/vsx/index.php?view=detail.top&oid=623474 ASASSN-18su was discovered on 2018 August 17. Unfortunately that outburst could be followed for only few days. After the seasonal gap a very long fading tail can be seen in ATLAS forced photometry data. T. Kato wrote (vsnet-alert 22429): "The Gaia proper motion is comparable to that of OV Boo ... ASASSN-18su looks likely a population II CV candidate." The current outburst was detected by Rod Stubbings at mv= 11.3 on 2022 June 28.537 UT (vsnet-outburst 28822, vsnet-alert 26852). It had already started on June 24 and is 1.5 magnitudes fainter than the 2018 outburst according to ASAS-SN Sky Patrol data: https://asas-sn.osu.edu/sky-patrol/coordinate/52d16cd1-3548-431f-a7fc-326e3… Time-resolved photometry is urgently required. 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-newvar 9370] TCP J15244460-6059200: strange Galactic nova (mag. 11) in Circinus
by Patrick Schmeer 27 Jun '22

27 Jun '22

TCP J15244460-6059200 (N) (submitted to VSX) RA 15h24m47.62s DE -60°59'47.3" (Gaia DR3, equinox and epoch J2000.0) Discoverer: Andrew Pearce (Nedlands, Western Australia) http://www.cbat.eps.harvard.edu/unconf/followups/J15244460-6059200.html Elias Aydi et al.: "SOAR spectroscopic follow-up of the Galactic optical transient TCP J15244460-6059200" (ATel #15473): https://www.astronomerstelegram.org/?read=15473 Quote: "The spectrum resembles that of a very fast classical nova after optical peak. The low amplitude of the transient raises questions about its nature and the possible progenitor match. TCP J15244460-6059200 could be an unusually low-amplitude, ultra-fast nova or a more exotic phenomenon. There is a slight chance that the actual progenitor system is much fainter and coincides with the bright (~14 mag) match, which would explain the unusually low- amplitude of the transient." The likely progenitor is the Gaia DR3 source 5875610751015084544 (Gmag. 13.75, BP-RP= 0.73, Teff ~22500 K, parallax 0.11 ± 0.02 mas, distance 6.5 ± 0.8 kpc). SMSS data: gPSF= 13.98, rPSF= 13.70, iPSF= 13.74 APASS data: V= 13.88, B= 14.35, g'= 14.08, r'= 13.70, i'= 13.65 So the eruption amplitude seems to be only 3 magnitudes! And the likely progenitor does not look like a typical CV in quiescence. ASAS-SN Sky Patrol (Shappee et al. 2014ApJ...788...48S and Kochanek et al. 2017PASP..129j4502K) light curves and data: https://asas-sn.osu.edu/sky-patrol/coordinate/63cd3b67-9d82-41da-869e-4d122… https://asas-sn.osu.edu/sky-patrol/coordinate/a61c2edb-9cab-4d5c-b9cf-f886b… TCPJ15244460-6059200 20220619.1200 14.00g ASN TCPJ15244460-6059200 20220625.2002 10.91g ASN TCPJ15244460-6059200 20220625.2015 10.92g ASN TCPJ15244460-6059200 20220625.2027 10.97g ASN TCPJ15244460-6059200 20220625.9486 12.00g ASN TCPJ15244460-6059200 20220625.9498 11.96g ASN TCPJ15244460-6059200 20220625.9510 12.00g ASN TCPJ15244460-6059200 20220626.2656 12.28g ASN TCPJ15244460-6059200 20220626.2668 12.27g ASN TCPJ15244460-6059200 20220626.2682 12.28g ASN TCPJ15244460-6059200 20220626.9602 12.71g ASN TCPJ15244460-6059200 20220626.9615 12.65g ASN TCPJ15244460-6059200 20220626.9628 12.81g ASN Could the apparent fading trend in ASAS-3 data be real? http://www.astrouw.edu.pl/cgi-asas/asas_variable/152448-6059.8,asas3,0,9755… Further spectroscopy and multiband photometry are required. Clear skies, Patrick

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[vsnet-newvar 9369] TCP J22561804+4109534: new transient (mag. 14) in Lacerta
by Patrick Schmeer 27 Jun '22

27 Jun '22

TCP J22561804+4109534 (UG:) (submitted to VSX) RA 22h56m18.05s +41°09'54.3" (J2000.0, Pan-STARRS1) 2022 June 26.6897 UT, mag. 14.0 (CMOS camera, unfiltered) Discoverer: Yuji Nakamura (Kameyama, Mie, Japan) 2022 06 26.6897 UT Discovered by Yuji Nakamura, Kameyama, Mie, Japan, on two frames (30-s exp. limiting mag 16.0) taken by 10cm/F3.0 refractor and CMOS camera. Nothing is visible at this location on the frames taken on 2022 June 18.7097 UT (30-s exp. limiting mag 16.0) by same instrument. --- Isao Endoh (NAOJ) http://www.cbat.eps.harvard.edu/unconf/followups/J22561804+4109534.html 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/a342649c-16c0-43e6-86f6-933b9… TCPJ22561804+4109534 20220624.4688 <17.55g ASN TCPJ22561804+4109534 20220626.3301 14.70g ASN TCPJ22561804+4109534 20220626.3314 14.76g ASN TCPJ22561804+4109534 20220626.3326 14.74g ASN TCPJ22561804+4109534 20220626.3379 14.71g ASN TCPJ22561804+4109534 20220626.3391 14.72g ASN TCPJ22561804+4109534 20220626.3404 14.69g ASN Time-resolved and multiband (V, B, ...) photometry are required (spectroscopy is also encouraged). Clear skies, Patrick

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[vsnet-newvar 9368] ASASSN-20pv bright again (AM CVn)
by Taichi Kato 22 Jun '22

22 Jun '22

ASASSN-20pv bright again (AM CVn) Brightening after fading following long standstill-like rebrightening. YYYYMMDD(UT) mag observer 20220528.506 148 (Rod Stubbings) 20220603.466 157 (Rod Stubbings) 20220621.426 143 (Rod Stubbings) 20220621.458 145 (Rod Stubbings)

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[vsnet-newvar 9367] Gaia22coq
by Taichi Kato 21 Jun '22

21 Jun '22

Gaia22coq http://gsaweb.ast.cam.ac.uk/alerts/alert/Gaia22coq/ Gaia22coq AT2022nbg 2022-06-18 14:45:10 331.72290 38.41940 17.55 unknown 2022-06-20 17:53:28 bright blue transient, rising fast

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[vsnet-newvar 9366] MGAB-V300: rebrightening from a possible AM CVn star
by Taichi Kato 20 Jun '22

20 Jun '22

MGAB-V300: rebrightening from a possible AM CVn star Type from ZTF data. Rapid fading (2 mag/d) and rebrightening in the past data. YYYYMMDD(UT) mag observer 20220612.2432 14.06C (Masao Funada) 20220612.3877 14.328zr (Zwicky Transient Facility Lasair (Masci+ 2019)) 20220614.3776 17.032zr (Zwicky Transient Facility Lasair (Masci+ 2019)) 20220614.4204 17.024zg (Zwicky Transient Facility Lasair (Masci+ 2019)) 20220615.163 <16.70C (Gary Poyner) 20220615.1640 <173C (Masao Funada) 20220617.715 16.45C (Hiroshi Itoh)

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[vsnet-newvar 9365] KLK-43 possible superoutburst
by Taichi Kato 20 Jun '22

20 Jun '22

KLK-43 possible superoutburst Type from ZTF data. YYYYMMDD(UT) mag observer 20220601.3839 16.619zg (Zwicky Transient Facility Lasair (Masci+ 2019)) 20220601.4591 16.455zr (Zwicky Transient Facility Lasair (Masci+ 2019)) 20220605.4019 16.620zr (Zwicky Transient Facility Lasair (Masci+ 2019)) 20220605.4425 16.718zg (Zwicky Transient Facility Lasair (Masci+ 2019)) 20220607.4141 17.081zg (Zwicky Transient Facility Lasair (Masci+ 2019)) 20220609.3992 17.148zg (Zwicky Transient Facility Lasair (Masci+ 2019)) 20220611.4205 17.404zg (Zwicky Transient Facility Lasair (Masci+ 2019))

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[vsnet-newvar 9364] CRTSJ141002.2-124809 possible superoutburst
by Taichi Kato 20 Jun '22

20 Jun '22

CRTSJ141002.2-124809 possible superoutburst Type from ZTF data. YYYYMMDD(UT) mag observer 20220617.1898 16.391zr (Zwicky Transient Facility Lasair (Masci+ 2019)) 20220617.2962 16.141zg (Zwicky Transient Facility Lasair (Masci+ 2019))

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[vsnet-newvar 9363] ASASSN-21mm outburst
by Taichi Kato 20 Jun '22

20 Jun '22

ASASSN-21mm outburst Relatively rare outburst. Subtype unknown. YYYYMMDD(UT) mag observer 20220611.3567 16.214zr (Zwicky Transient Facility Lasair (Masci+ 2019)) 20220613.3152 16.233zr (Zwicky Transient Facility Lasair (Masci+ 2019)) 20220613.3769 16.187zg (Zwicky Transient Facility Lasair (Masci+ 2019))

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vsnet-newvar June 2022