[Iaude] CBET 5365: V4370 OPHIUCHI = NOVA OPHIUCHI 2024

[quai at eps.harvard.edu]

                                                  Electronic Telegram No. 5365
Central Bureau for Astronomical Telegrams
Mailing address:  Hoffman Lab 209; Harvard University;
 20 Oxford St.; Cambridge, MA  02138; U.S.A.
e-mail:  cbatiau at eps.harvard.edu (alternate cbat at iau.org)
URL http://www.cbat.eps.harvard.edu/index.html
Prepared using the Tamkin Foundation Computer Network


V4370 OPHIUCHI = NOVA OPHIUCHI 2024 = TCP J17395720-2627410
     Several independent discoveries of an apparent nova were received by the
Central Bureau on Mar. 10 UT.  The first arrived from Tadashi Kojima at
Tsumagoi, Gunma-ken, Japan, who reported the variable at mag 11.5 on three
unfiltered 5-s exposures (limiting mag 12.8) taken on Mar. 10.775 with a
Canon EOS 6D camera (+ 200-mm-f.l. f/3.2 lens).  Kojima gave the position as
R.A. = 17h39m57s.20, Decl. = -26d27'41".0 (equinox J2000.0), and when he
posted it at the Bureau's TOCP webpage, it was assigned the designation TCP
J17395720-2627410.  Kojima adds that nothing was visible at this position on
images taken on Mar. 6.807 (limiting mag 13.2), and that the star had risen
to mag 11.3 by Mar. 10.784.
     An apparently independent discovery was reported soon thereafter by
Koichi Itagaki (Yamagata, Japan), on an unfiltered exposure taken on Mar.
10.818 UT, with the magnitude given as 10.9 and the position end figures as
56s.99, 41".3.  No information was provided about the instrumentation.  He
later reported position end figures 57s.09, 41".8 from a CCD frame taken on
Mar. 10.846 with a 0.35-m f/11 telescope, and he posted his image at website
URL http://k-itagaki.jp/images/Oph-2024-03.jpg.  When Itagaki posted his
discovery to the TOCP, it received the designation TCP J17395699-2627413.
     I. Endoh, National Astronomical Observatory of Japan, reported the
following information from independent discoveries of TCP J17395720-2627410:
Mar. 10.797 UT, mag 11.1, position end figures 57s.20, 43".1 (Yuji Nakamura,
Kameyama, Mie, Japan; two 6-s exposures, limiting mag 13.0, 135-mm-f.l. lens
+ CMOS camera); Mar. 10.807, mag 11.1, position end figures 57s.28, 41".2
(Minoru Yamamoto, Okazaki, Aichi, Japan; three exposures taken with a Canon
EOS 6D camera + 180-mm-f.l. lens; limiting mag 15.0); Mar. 10.825, mag 10.4,
position end figures 56s.97, 39".6 (Shigehisa Fujikawa, Kan'onji, Kagawa,
Japan; digital camera + 120-mm-f.l. lens).
     Andrew Pearce, Nedlands, Western Australia, reported another independent
discovery of TCP J17395720-2627410 on three images atken on Mar. 10.772 UT
with a Canon 800D camera (+ 85-mm-f.l. f/1.2 lens), adding that it was not
visible on images taken on Mar. 8.772 or 9.771 UT (limiting magnitude 12.0).
An unfiltered CCD image taken remotely on Mar. 11.320 by Pearce using a 0.35-m
f/7.2 reflector at Rio Hurtado Valley, Chile, shows TCP J17395720-2627410 at
mag 10.2 with position end figures 57s.08, 41".7 (Gaia DR2 positions), adding
that this position is 0".85 away from a Gaia star of G magnitude 18.9
(Gaia DR3 4061829569164264576).  CCD photometry from Pearce using a 0.50-m
f/6.8 reflector at Siding Spring, NSW, Australia on Mar. 11.685:  B = 12.89,
V = 11.15.
     Additional magnitudes reported to the Bureau for TCP J17395720-2627410:
Feb. 27.816 UT [13.0 (Nakamura); Mar. 9.81, [15 (Yamamoto); 10.852, 10.4 (A.
Takao, Kitakyushu, Japan; position end figures 56s.97, 44".6); 10.852, 10.9
(Fujikawa; 400-mm-f.l. lens); 11.107, V = 10.3 (S. Korotkiy, K. Sokolovsky,
S. Ostapenko, V. Belousov, and N. Potapov, 135-mm-f.l. f/2 telephoto lens +
unfiltered CCD camera, apparently in Russia); 11.249, 10.3 (A. Amorim,
Florianopolis, Brazil, 0.09-m refractor, visual); 11.296, B = 11.75, V =
10.34, I = 7.82 (K. Yoshimoto, Yamaguchi, Japan, using a 0.51-m f/6.8
corrected Dall-Kirkham telescope + CMOS remotely at "Deep Sky Chile"; position
end figures 57s.08, 42".0).  Yoshimoto posted his image posted at website
URL http://orange.zero.jp/k-yoshimoto/TCP_J17395720-2627410_20240311.jpg.
     M. Uemura and T. Nakaoka, Hiroshima University, report that a spectra
obtained on Mar. 10.84 UT with the 1.5-m "Kanata" telescope at the Higashi-
Hiroshima Astronomical Observatory show broad Balmer (H_alpha, H_beta) and
He I emission lines with P-Cyg profiles and a deep Na D absorption line; the
H_alpha emission component shows equivalent width about 2.0 nm and FWZI 4700
km/s (see website URL https://www.astronomerstelegram.org/?read=16521.  The
features suggest that TCP J17395720-2627410 is a highly reddened He/N-class
nova at an early phase.
     E. Kazarovets writes that the permanent GCVS designation V4370 Oph has
been given to this nova.


NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2024 CBAT
2024 March 11                    (CBET 5365)              Daniel W. E. Green