- vsnet-campaign-nova - ooruri.kusastro.kyoto-u.ac.jp

[vsnet-campaign-nova 2299] VY Scl fading
by Taichi Kato 26 Jul '23

26 Jul '23

VY Scl fading As pointed out by Rod Stubbings. YYYYMMDD(UT) mag observer 20230614.4047 13.381g (ASAS-SN Sky Patrol Photom. DB (Hart+2023; Shappee+2014)) 20230616.2739 13.649g (ASAS-SN Sky Patrol Photom. DB (Hart+2023; Shappee+2014)) 20230617.3584 13.664g (ASAS-SN Sky Patrol Photom. DB (Hart+2023; Shappee+2014)) 20230619.2794 13.115g (ASAS-SN Sky Patrol Photom. DB (Hart+2023; Shappee+2014)) 20230623.0134 13.247g (ASAS-SN Sky Patrol Photom. DB (Hart+2023; Shappee+2014)) 20230624.0234 13.387g (ASAS-SN Sky Patrol Photom. DB (Hart+2023; Shappee+2014)) 20230625.2558 13.569g (ASAS-SN Sky Patrol Photom. DB (Hart+2023; Shappee+2014)) 20230626.2966 13.750g (ASAS-SN Sky Patrol Photom. DB (Hart+2023; Shappee+2014)) 20230629.2510 13.650g (ASAS-SN Sky Patrol Photom. DB (Hart+2023; Shappee+2014)) 20230630.4389 14.046g (ASAS-SN Sky Patrol Photom. DB (Hart+2023; Shappee+2014)) 20230702.2937 13.475g (ASAS-SN Sky Patrol Photom. DB (Hart+2023; Shappee+2014)) 20230703.3364 13.478g (ASAS-SN Sky Patrol Photom. DB (Hart+2023; Shappee+2014)) 20230705.2270 13.728g (ASAS-SN Sky Patrol Photom. DB (Hart+2023; Shappee+2014)) 20230708.4395 13.474g (ASAS-SN Sky Patrol Photom. DB (Hart+2023; Shappee+2014)) 20230711.5528 141 (Rod Stubbings) 20230712.5667 140 (Rod Stubbings) 20230715.6410 144 (Rod Stubbings) 20230716.7431 141 (Rod Stubbings) 20230717.5549 144 (Rod Stubbings) 20230725.505 <153 (Rod Stubbings)

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[vsnet-campaign-nova 2298] No 0.1-d period in V2491 Cyg
by Taichi Kato 13 Jul '23

13 Jul '23

No 0.1-d period in V2491 Cyg https://ui.adsabs.harvard.edu/abs/2011A%26A...530A..70D/abstract "On the progenitor system of Nova V2491 Cygni" No such period was detected in the ZTF data. Two time-resolved runs in the ZTF data did not show any sign of such a period. The detection by this paper was probably spurious. There was no sign of the reported possible spin period (see Zemko et al. 2015).

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[vsnet-campaign-nova 2297] NSV21190: eclipsing symbiotic star currently undergoing symbiotic nova outburst?
by Taichi Kato 07 Jul '23

07 Jul '23

NSV21190: eclipsing symbiotic star currently undergoing symbiotic nova outburst? Yamamoto had reported brightening of this object in April. YYYYMMDD(UT) mag observer 20230422.744 132c (Minoru Yamamoto) Tadashi Kojima-san has reported that the object has been bright for months. object YYYYMMDD(UT) mag code NSV21190 20230331.758 128c Tko.VSOLJ NSV21190 20230517.629 128c Tko.VSOLJ NSV21190 20230617.503 128c Tko.VSOLJ NSV21190 20230706.553 127c Tko.VSOLJ This object has been suggested to be a large-amplitude variable star TerzV910 (suspected to be a Mira star based on IRAS identification). ASAS-SN data https://asas-sn.osu.edu/sky-patrol/coordinate/d5a29922-5bc0-4e1e-824e-086ac… and ATLAS observations suggest that this object appears to be an eclipsing symbiotic object, rather than a Mira star, which became active (at least) in in 2017. The minima occurred JD 2458240:, 2458660, 2459060: (P about 410 d?). The object once became faint in later 2020-later 2021, and then brightened to the current bright state. A shallow minimum around JD 2459830 during the present bright state may be an eclipse (the period then is around 400 d). The object was faint during ASAS-3 observations (2000-2009). The object is currently slowly brightening and would be another symbiotic nova (the shallow eclipse may be explained by a nova photosphere). The position is somewhat different between 2MASS and Gaia: 2MASS 171453.440 -283746.69 (2000.0) 15.129 12.170 9.707 171453.437 -283746.95 (2000.0) Gaia_DR2_4107611274955676672 plx=-(-) dismod=- pmra=-(-) pmdec=-(-) G=19.526 BP=20.104 RP=17.634 171453.437 -283746.96 (2000.0) Gaia_EDR3_4107611274955676672 plx=2.187(0.418) dismod=8.3 pmra=-6.604(0.411) pmdec=-7.609(0.337) G=19.598 BP=20.516 RP=18.301 I used the 2MASS location.

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[vsnet-campaign-nova 2296] PGIR22akgylf peak magnitude
by Taichi Kato 21 Mar '23

21 Mar '23

PGIR22akgylf peak magnitude https://www.aavso.org/vsx/index.php?view=detail.top&oid=2344400 YYYYMMDD(UT) mag observer 20221228.3505 13.35V (Seiichiro Kiyota) 20221228.4609 13.20V (Masayuki Moriyama)

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[vsnet-campaign-nova 2295] Re: Gaia23azk
by Taichi Kato 08 Mar '23

08 Mar '23

Re: Gaia23azk No past activity in ASAS-SN/ATLAS. https://asas-sn.osu.edu/sky-patrol/coordinate/9c515a17-75cd-480d-98e9-f5a7c…

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[vsnet-campaign-nova 2294] Re: Gaia23azk
by Taichi Kato 08 Mar '23

08 Mar '23

Re: Gaia23azk > Bright transient. What is it? Reddened nova? Emission line in the spectrum? YYYYMMDD(UT) mag observer 20230306.6405 15.094o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230306.6446 15.081o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230306.6519 15.044o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230306.6626 15.040o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230307.3733 14.790o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230307.3751 14.869o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230307.3917 14.823o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505))

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[vsnet-campaign-nova 2293] 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-campaign-nova 2292] 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-campaign-nova 2291] 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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[vsnet-campaign-nova 2290] GI Mon: currently dwarf nova
by Taichi Kato 08 Jan '23

08 Jan '23

GI Mon: currently dwarf nova Using ATLAS forced photometry (Tonry et al. 2018; Shingles et al. 2021), I found that this object is currently a dwarf nova with 1 mag amplitude (see also vsnet-chat 8458). The light curve since 2019 resembles an IW And star (heartbeat state). The current cycle length is about 70 d.

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