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

[vsnet-alert 27442] MASTER OT J055845.55+391533.4 outburst (likely AM CVn)
by Taichi Kato 22 Feb '23

22 Feb '23

MASTER OT J055845.55+391533.4 outburst (likely AM CVn) Maeda-san detected an outburst at 14.0 on Feb. 21. Supercycle 220-400 d (ZTF data).

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[vsnet-alert 27441] CCD observations of TCP J17562787-1714548 = Nova Sgr 2023
by Filipp Romanov 21 Feb '23

21 Feb '23

Observer: Filipp Romanov (AAVSO, Russia). Remotely using iTelescope.Net T11 (0.50-m f/6.8 reflector + CCD + f/4.5 focal reducer) in Utah Desert Remote Observatory at Great Basin Desert, Beryl Junction, Utah, USA. TCPJ17562787-1714548 20230221.52963 10.315I RFD 0.006 TCPJ17562787-1714548 20230221.52866 10.718R RFD 0.003 TCPJ17562787-1714548 20230221.52767 12.625B RFD 0.003 TCPJ17562787-1714548 20230221.52660 11.879V RFD 0.001 TCPJ17562787-1714548 20230221.52557 10.322I RFD 0.009 TCPJ17562787-1714548 20230221.52459 10.715R RFD 0.004 TCPJ17562787-1714548 20230221.52360 12.648B RFD 0.005 TCPJ17562787-1714548 20230221.52255 11.884V RFD 0.002 Color image (3x60 sec. with V, B, Rc filters): https://www.flickr.com/photos/filipp-romanov/52702897703/ With best wishes, Filipp.

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[vsnet-alert 27440] Re: Spectrum of TCP J06442271+1549388
by Taichi Kato 21 Feb '23

21 Feb '23

Re: Spectrum of TCP J06442271+1549388 > We reported optical spectrum of TCP J17562787-1714 to ATel #15911 and > classify it as a He/N-type nova: V407 Cyg erupted in symbiotic environment and a fast nova. These features are not exclusive. Could be a nova similar to V407 Cyg?

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[vsnet-alert 27438] TCP J17562787-1714548 (ATEL 15910)
by Taichi Kato 21 Feb '23

21 Feb '23

TCP J17562787-1714548 (ATEL 15910) > It is somewhat unusual for a nova to show shock-powered X-rays > visible to Swift/XRT less than two days after eruption. This may > suggest that the transient is a very fast nova and/or a nova > embedded in the wind of an evolved donor star. Possibly a nova that erupted in symbiotic environment. === ATEL #15910 ATEL #15910 Title: Swift/XRT detection of the nova candidate TCP J17562787-1714548 Author: Kirill Sokolovsky (UIUC), Kim Page (U. Leicester), Elias Aydi, Laura Chomiuk, Jay Strader (MSU), Jennifer Sokoloski (Columbia), Justin Linford (NRAO), Koji Mukai (NASA/GSFC) Queries: kirx(a)kirx.net Posted: 21 Feb 2023; 01:02 UT Subjects:Ultra-Violet, X-ray, Nova, Transient The candidate nova TCP J17562787-1714548 was discovered by Y. Sakurai, H. Nishimura, and A. Pearce using DSLR camera images with the first reported detection on 2022-02-18.834 UT at an unfiltered magnitude of 11. Follow-up astrometry by multiple observers reported via CBAT Transient Object Followup Reports page suggests Gaia DR3 4144602552564272000 (G=18.1, Plx=0.20+/-0.18 mas) as a possible progenitor that shows irregular variability in archival ZTF and ATLAS photometry (T. Kato, vsnet-alert 27432). Swift observed TCP J17562787-1714548 for 1.9ks on 2023-02-20.58. Swift/XRT detected an X-ray source with a net count rate of 0.043 +/-0.006 cts/s at the position of the transient. Most of the counts are above 3 keV, consistent with heavily absorbed (n_H > 10^23 cm^-2) thermal emission with kT > 1 keV. The Galactic absorbing column density in the direction of the source is n_H = 3.86x10^21 cm^-2 (Kalberla et al. 2005 A&A, 440, 775), suggesting the presence of source-intrinsic absorption. The XRT detection cannot be attributed to optical loading that should manifest itself as spurious soft (rather than hard) emission. Swift/UVOT detected a UVW1= 12.35 +/-0.02 (Vega system) ultraviolet source at the position of the transient. It is somewhat unusual for a nova to show shock-powered X-rays visible to Swift/XRT less than two days after eruption. This may suggest that the transient is a very fast nova and/or a nova embedded in the wind of an evolved donor star. We thank the Neil Gehrels Swift Observatory team and PI, Brad Cenko, for rapid execution this ToO observation. <a href="https://ztf.snad.space/dr13/view/332207100098232">ZTF photometry of the possible progenitor</a> CBAT Transient Object Followup Reports page: http://www.cbat.eps.harvard.edu/unc onf/followups/J17562787-1714548.html

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[vsnet-alert 27437] CRTS J174033.4+414756 superoutburst continues
by Taichi Kato 21 Feb '23

21 Feb '23

CRTS J174033.4+414756 superoutburst continues YYYYMMDD(UT) mag observer 20230128.5155 19.929zr (ZTF Alert DC mag (Masci+ 2019)) 20230130.8567 <159c (Yutaka Maeda) 20230204.5406 14.241zr (ZTF Alert DC mag (Masci+ 2019)) 20230204.8568 123cG (Yutaka Maeda) 20230204.8568 123cG (Yutaka Maeda) 20230207.149 13.15CV (Klaus Wenzel) 20230207.160 131 (Klaus Wenzel) 20230209.137 132CV (Klaus Wenzel) 20230209.5379 14.331zg (ZTF Alert DC mag (Masci+ 2019)) 20230213.201 136CV (Klaus Wenzel) 20230214.8331 134cG (Yutaka Maeda) 20230215.8377 135cG (Yutaka Maeda) 20230220.196 141CV (Klaus Wenzel)

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[vsnet-alert 27436] CSS J091017.4-200812: AM CVn-type superoutburst
by Taichi Kato 21 Feb '23

21 Feb '23

CSS J091017.4-200812: AM CVn-type superoutburst Berto Monard has reported observations. Based on a single-night run, superhumps with a period of 0.0205(1) d and amplitude of 0.07 mag were detected.

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[vsnet-alert 27435] BE Oct superoutburst
by Taichi Kato 20 Feb '23

20 Feb '23

BE Oct superoutburst YYYYMMDD(UT) mag observer 20230214.505 163 (Rod Stubbings) 20230218.453 156 (Rod Stubbings) 20230219.473 158 (Rod Stubbings)

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[vsnet-alert 27434] V392 Hya standstill
by Taichi Kato 20 Feb '23

20 Feb '23

V392 Hya standstill YYYYMMDD(UT) mag observer 20230105.2652 15.041o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230105.2872 15.018o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230105.2899 15.030o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230105.2949 15.031o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230107.0476 14.727o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230107.0496 14.741o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230107.0528 14.739o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230107.0628 14.723o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230107.8663 148C (Masayuki Moriyama) 20230108.0163 14.748o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230108.0181 14.717o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230108.0210 14.724o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230108.0283 14.724o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230108.589 145 (Rod Stubbings) 20230109.2903 14.695o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230109.2934 14.696o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230109.2965 14.702o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230109.3021 14.710o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230113.3260 15.05C (Masao Funada) 20230113.581 148 (Rod Stubbings) 20230114.571 150 (Rod Stubbings) 20230120.574 148 (Rod Stubbings) 20230120.8603 150C (Masayuki Moriyama) 20230122.594 148 (Rod Stubbings) 20230127.274 15.18C (Gary Poyner) 20230127.2760 15.37cG (Masao Funada) 20230127.608 150 (Rod Stubbings) 20230131.556 148 (Rod Stubbings) 20230208.0624 15.09C (Masao Funada) 20230208.062 15.14C (Gary Poyner) 20230210.499 148 (Rod Stubbings) 20230213.533 149 (Rod Stubbings) 20230214.533 148 (Rod Stubbings) 20230217.176 15.04C (Gary Poyner) 20230217.1786 15.17cG (Masao Funada) 20230219.492 148 (Rod Stubbings)

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[vsnet-alert 27433] MGAB-V300 outburst (suspected AM CVn)
by Taichi Kato 20 Feb '23

20 Feb '23

MGAB-V300 outburst (suspected AM CVn) YYYYMMDD(UT) mag observer 20230218.5603 15.430zr (ZTF Alert DC mag (Masci+ 2019)) 20230218.5627 15.369zr (ZTF Alert DC mag (Masci+ 2019)) 20230218.5652 15.425zr (ZTF Alert DC mag (Masci+ 2019))

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[vsnet-alert 27432] TCP J17562787-1714548
by Taichi Kato 20 Feb '23

20 Feb '23

TCP J17562787-1714548 http://cbat.eps.harvard.edu/unconf/followups/J17562787-1714548.html The quiescent counterpart 2MASS 175627.896 -171453.26 (2000.0) 15.474 13.516 13.211 175627.901 -171453.72 (2000.0) Gaia_DR2_4144602552564272000 plx=0.198(0.244) dismod=13.5 pmra=0.263(0.373) pmdec=-7.070(0.330) G=18.124 BP=18.710 RP=17.038 175627.901 -171453.73 (2000.0) Gaia_EDR3_4144602552564272000 plx=0.202(0.187) dismod=13.5 pmra=0.851(0.177) pmdec=-6.670(0.121) G=18.119 BP=18.871 RP=17.093 was relatively variable both in ZTF and ATLAS. Nova containing a giant? (such as a symbiotic one)

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