4 May 2010
IAU Circular No.9142--------------------------------------------------------------------------------
V1311 SCORPII = NOVA SCORPII 2010 No. 2
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As first announced on CBET 2262, K. Nishiyama (Kurume, Japan)
and F. Kabashima (Miyaki, Japan) report their discovery of another
possible Milky Way nova (mag 8.6) on two unfiltered CCD frames
(limiting mag 13.1) taken around Apr. 25.788 UT using a 105-mm f/4
camera lens. Follow-up unfiltered CCD frames (limiting mag 17.3)
taken around Apr. 25.796 using a 0.40-m reflector yield the
following precise position for the variable: R.A. = 16h55m13s.16,
Decl. = -38o03'46".9 (equinox 2000.0). Additional magnitudes
(obtained via unfiltered CCD unless otherwise noted) for the new
variable: 1995 June 4, [18.0 (Digitized Sky Survey, red plate; via
Nishiyama and Kabashima); 2010 Apr. 23.786, [12.9 (Nishiyama and
Kabashima); 24.74, [10.2: (Y. Sakurai, Mito, Ibaraki-ken, Japan);
24.757, [13.2 (Nishiyama and Kabashima); 25.734, 8.8 (Sakurai;
measured by S. Nakano, Sumoto, Japan; independent discovery);
25.738, 8.8 (T. Kojima, Tsumagoi, Agatsuma-gun, Gunma-ken, Japan;
measured by Nakano; independent discovery); 25.763, 8.3 (H.
Nishimura, Miyawaki, Kakegawa, Shizuoka-ken, Japan, via Nakano;
independent discovery); 26.307, V = 8.55 (S. Kiyota, Tsukuba,
Japan, 30-cm reflector; position end figures 13s.22, 46".8);
26.308, R_c = 7.75 (Kiyota); 26.309, I_c = 6.92 (Kiyota); 26.310, B
= 10.18 (Kiyota); 26.4, about 8.2 (E. Guido and G. Sostero; 0.25-m
reflector; position end figures 13s.17, 47".8); 27.21, 10.3 (H.
Koberger and W. Vollmann, 0.6-m reflector at Tenerife; position end
figures 13s.16, 46".9); 29.680, I_c = 8.77 (H. Maehara, Kwasan
Observatory); 29.681, R_c = 9.45 (Maehara); 29.683, V = 11.21
(Maehara); 29.685, B = 12.03 (Maehara). Visual magnitude estimates:
Apr. 27.154 UT, 11.0 (A. Amorim, Florianopolis, Brazil); May 2.010,
11.9 (Amorim); 4.424, 12.9 (M. Linnolt, Ocean View, HI, U.S.A., via
the AAVSO). Maehara's spectrogram from Apr. 29.704 UT (25-cm
telescope) shows H_alpha and H_beta emission lines with a FWMH of
4000 km/s. Additional details appear also on CBET 2265. E.
Kazarovets, Russian Academy of Sciences, writes that the GCVS
designation V1311 Sco has been assigned to this nova.
K. Kinugasa, H. Takahashi, and O. Hashimoto, Gunma
Astronomical Observatory (GAO), write that a low-dispersion
spectrum (range 420-850 nm, resolution about 500) of this object,
taken on Apr. 29.745 UT with the GAO 1.5-m telescope (+ GLOWS),
shows broad (FWHM about 4000 km/s) Balmer and O I (777.4-, 822.7-,
and 844.6-nm) emission lines. Both H_alpha and H_beta have
asymmetric line profiles with a blue peak. Several emission lines
of He I and N II are also seen. The features indicate that the
object is a He/N nova in a declining phase. Their spectrum can be
viewed at the following website URL:
http://tinyurl.com/37r6yhj.
2010 May 4 (9142) Daniel W. E. Green