From tkato@kusastro.kyoto-u.ac.jp Tue Feb 21 01:24:27 2023
From: Taichi Kato <tkato@kusastro.kyoto-u.ac.jp>
To: vsnet-campaign-nova@ooruri.kusastro.kyoto-u.ac.jp
Subject: [vsnet-campaign-nova 2292] TCP J17562787-1714548 (ATEL 15910)
Date: Tue, 21 Feb 2023 10:24:22 +0900
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TCP J17562787-1714548 (ATEL 15910)

> It is somewhat unusual for a nova to show shock-powered X-rays =20
> visible to Swift/XRT less than two days after eruption. This may =20
> suggest that the transient is a very fast nova and/or a nova =20
> embedded in the wind of an evolved donor star.

   Possibly a nova that erupted in symbiotic environment.

=3D=3D=3D

ATEL #15910                                                          ATEL #15=
910

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 (Columbi=
a),
 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 =20
Y. Sakurai, H. Nishimura, and A. Pearce using DSLR camera images =20
with the first reported detection on 2022-02-18.834 UT at =20
an unfiltered magnitude of 11. Follow-up astrometry by multiple =20
observers reported via CBAT Transient Object Followup Reports page =20
suggests Gaia DR3 4144602552564272000 (G=3D18.1, Plx=3D0.20+/-0.18 mas) =20
as a possible progenitor that shows irregular variability =20
in archival ZTF and ATLAS photometry (T. Kato, vsnet-alert 27432). =20

Swift observed TCP J17562787-1714548 for 1.9ks on 2023-02-20.58. =20
Swift/XRT detected an X-ray source with a net count rate =20
of 0.043 +/-0.006 cts/s at the position of the transient. =20
Most of the counts are above 3 keV, consistent with =20
heavily absorbed (n_H > 10^23 cm^-2) thermal emission =20
with kT > 1 keV. The Galactic absorbing column density in =20
the direction of the source is n_H =3D 3.86x10^21 cm^-2 =20
(Kalberla et al. 2005 A&A, 440, 775), suggesting the presence of =20
source-intrinsic absorption. The XRT detection cannot be attributed =20
to optical loading that should manifest itself as spurious =20
soft (rather than hard) emission. Swift/UVOT detected =20
a UVW1=3D 12.35 +/-0.02 (Vega system) ultraviolet source at =20
the position of the transient. =20

It is somewhat unusual for a nova to show shock-powered X-rays =20
visible to Swift/XRT less than two days after eruption. This may =20
suggest that the transient is a very fast nova and/or a nova =20
embedded in the wind of an evolved donor star. =20

We thank the Neil Gehrels Swift Observatory team and PI, =20
Brad Cenko, for rapid execution this ToO observation.=20

<a href=3D"https://ztf.snad.space/dr13/view/332207100098232">ZTF photometry
of the possible progenitor</a>=20

CBAT Transient Object Followup Reports page: http://www.cbat.eps.harvard.edu/=
unc
onf/followups/J17562787-1714548.html

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