Flare stars
Automatic discovery of an outburst of a flare star - RXJ0413.4-0139
The wide field "Pi of the Sky North"
apparatus installed in the BOOTES-1 station at ESAt/INTA-CEDEA in Mazagon
(Huelva, Spain) identified an outburst within its field of view at 23:28:38 UT
on November 24, 2011. New source was visible at position (J2000): RA =
4h 13m 27.15s , DEC = -1° 39′
29″.
The measured position coincides within estimated position error of
about 10″ with
2MASS J04132663-0139211 star. McCarthy et
al. discovered in 2001, that this is a double star system with
M4e spectral type, their name is RX J0413.4-0139. A lot of information about this star spectroscopy
is also available in the paper E Shkolnik et al., 2009 where its name is 1RXS J041325.8-013919. Addtional articles which contain
information about this star are: C. Bergfors et
al., 2010, J04132663-0139211 and I. Neill Reid et al.
2007, RX J0413- 0139.
According to Taichi Kato
from vsnet the observation is most likely a dM4e-type star during an outburst
stage.
According to the following comment by Kato
(http://ooruri.kusastro.kyoto-u.ac.jp/mailarchive/vsnet-alert/13907):
"Javier Ruiz has reported unfiltered photometry of this transient
on Nov. 27 and recorded another large flare (2.7 mag in amplitude).
This object appears to be an active flare star".
We checked the ASAS database,
where there is a star within more or less 15″, which generally did not exceed
a magnitudo of 13.5, but in December 23rd 2002 the star went an
outburst, when reached 12.1 magnitudo.
Follow up observations of the outburst were made by Bootes-1 group in Spain
and Bob Sandness at Alain Maury's SPACE observatory at San Pedro de Atacama,
Chile. Both observations indicate a second, longer outburst about 3 hours
later. Data analysis is ongoing.
Images below cover 1°x1°, 10 s exposure each, from about 23:14:53
to 23:29:54 UT. There are 72 single frames:
a
Our light curve (click in the picture to enlarge) and some of our data points:
 |
| Our data: |
| HJD | Date UT | Time UT | magnitude cam36 |
|---|
| 2455890.48334669 | 2011.11.24 | 23:28:26 | 12.018 |
| 2455890.48348558 | 2011.11.24 | 23:28:38 | 11.803 |
| 2455890.48362447 | 2011.11.24 | 23:28:51 | 12.009 |
| 2455890.48378650 | 2011.11.24 | 23:29:04 | 11.886 |
| 2455890.48391382 | 2011.11.24 | 23:29:16 | 12.239 |
| 2455890.48406428 | 2011.11.24 | 23:29:29 | 12.277 |
