Variable Stars - TCP J17154683-3128303
Type Novae Novae. Close binary systems with orbital periods from 0.05 to 230 days. One of the components of these systems is a hot dwarf star that suddenly, during a time interval from one to several dozen or several hundred days, increases its brightness by 7-19 mag. in V, then returns gradually to its former brightness over several months, years, or decades. Small changes at minimum light may be present. Cool components may be giants, subgiants, or dwarfs of K-M type. The spectra of novae near maximum light resemble A-F absorption spectra of luminous stars at first. Then broad emission lines (bands) of hydrogen, helium, and other elements with absorption components indicating the presence of a rapidly expanding envelope appear in the spectrum. As the light decreases, the composite spectrum begins to show forbidden lines characteristic of the spectra of gas nebulae excited by hot stars. At minimum light, the spectra of novae are generally continuous or resemble the spectra of Wolf- Rayet stars. Only spectra of the most massive systems show traces of cool components. Some novae reveal pulsations of hot components with periods of approximately 100 s. and amplitudes of about 0.05 mag. in V after an outburst. Some novae eventually turn out to be eclipsing systems. According to the features of their light variations, novae are subdivided into fast (NA), slow (NB), very slow (NC), and recurrent (NR) categories. AAVSO Alert 383: March 27, 2014 Koichi Nishiyama (Kurume, Japan) and Fujio Kabashima (Miyaki, Japan) report their discovery of a transient in Scorpius: They confirmed the discovery on unfiltered CCD frames taken around 2014 Mar 26.86981 UT. Survey frames from 2014 Mar 22.819 UT (limiting mag.= 12.5) and 23.836 UT (limiting mag.= 12.9) show no object, nor does DSS or USNO-B1.0. The nearest star in the DENIS Database has position end figures 46.861s, 30.48", distance 0.44", magnitude I=14.222. ATel #6015 (E. Kuulkers et al.) reports that Swift observations taken only hours after the discovery (March 27 03:39-03:51 and 04:42-04:51 UT) reveal a new, bright, X-ray source. The source is also seen in UVOT, with uvw1 magnitudes of 12.58 +/- 0.02 and 12.61 +/- 0.02, for the 2 snapshots, respectively. The positions they derive are consistent with the optical discovery position. The mean X-ray spectrum is consistent with an (expanding) shell in a nova. The position was covered during an XMM-Newton slew on UT 2011 March 4, but no source was seen with a 0.2-12 keV 2-sigma upper limit of 0.54 c/s. Follow-up Swift ToO observations for the next days have been approved.
Hills Observatory: 1 January 2013 to 28 December 2020