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    MisV1446: Outburst of an X-ray Source    

2012 Feb. 3
Seiichi Yoshida / MISAO Project

On January 9, 2012, we the MISAO Project discovered a new dwarf nova, outburst of an X-ray source, from the survey images taken by Youichirou Nakashima.

o Recent Observations (Updated on June 14, 2015)

o Recent Images (Updated on Feb. 3, 2012)


Variation of MisV1446 (Image: Youichirou Nakashima)
Field of view: about 8 arcmin.

This dwarf nova was discovered by Seiichi Yoshida (MISAO Project) in the MISAO Project nova survey. It was picked up as one of the nova candidates from Youichirou Nakashima (Okayama, Japan)'s unfiltered CCD images on 2012 Jan. 5 by the PIXY System 2. It locates at R.A. 07h41m12s.70, Decl. -09o45'55".9 (equinox J2000.0) and the brightness was 14.1 mag.

This object was not found on the past images of the MISAO Project from Jan. 15 to Dec. 24 in 2011 by Nakashima with a limiting magnitude of 14.6-15.6 mag.

Yoshida confirmed that it is not a known asteroid using the Minor Planet Checker. Yoshida also confirmed that it is not an infrared object using the 2MASS images.

The SIMBAD database shows an X-ray source 1RXS J074112.2-094529 exists near by this position. So it seemed to be an outburst of this X-ray source.

Immediately, Diego Rodriguez confirmed the outburst of this object. It was 14.65-14.66 mag on Jan. 8.919 and 8.923 on his unfiltered CCD images with LX200 25cm f/6.3 and ST8XME. Then we the MISAO Project assigned a new variable star designation MisV1446 to this star.

We have discovered another dwarf nova MisV1443 just one year ago, on 2011 Jan. 10 (see MisV1443: Discovery of Bright Dwarf Nova in Orion).

Hidetaka Sato observed multi-band photometry on Jan. 9, and confirmed that this star is bluish. Here is the report published at the CBAT Transient Objects Confirmation Page (TOCP).

2012 01 09.0644

V-band mag = 14.74 +/- 0.04. R-band mag = 14.55 +/- 0.01, I-Band mag = 14.36 +/- 0.01 by Hidetaka Sato, Ota-ku, Tokyo, Japan. Position end figures 12s.72, 56".2 (USNO-A2.0), remotely using 0.43-m f/4.5 reflector + CCD (EV2 CCD47-10-1-109) at iTelescope Astrocamp Observatory, Nerpio, Spain (MPC-I89). Magnitudes were measured on each two images of 60 seconds (V) or 30 seconds (R and I) of exposure under 17.5 V, 18.0 R, 17.5 I of the limiting magnitude at 1.5 of airmass. The position was derived from two co-added images of R-band exposure. The standard stars were taken on Landolt SA98-666, 670, 671 and 685 at 1.5 of airmass.

Luca Buzzi Federica Luppi observed this object on Jan. 10. Here is the report published at the CBAT Transient Objects Confirmation Page (TOCP).

2012 01 10.965

This transient was observed by Luca Buzzi and Federica Luppi from Schiaparelli Observatory, Varese, Italy. In a single unfiltered 30 seconds image, it has position end figures 12s.71, 56".0 and magnitude 14.8. A star is visible in DSS red and blue images at position end figures 12s.71, 56".2 and magnitude 17.4 R. Image posted at URL: http://www.astrogeo.va.it/pub/TOCP/TCP_J07411270-0945559.jpg

Taichi Kato, Kyoto University, commented that GSC 2.3.2 has a 19.1(Bj) mag counterpart. The object looks like a dwarf nova with a relatively large outburst amplitude.

Taichi Kato and Tomohito Ohshima, VSNET, reported that observations between Jan. 11 and 15 by Seiichiro Kiyota, Kiyoshi Kasai, William Stein, Berto Monard, and Enrique de Miguel detected superhumps with a period of 0.07786 (7) days, confirming the SU UMa-type nature of this object. The amplitude of the superhumps was 0.2 mag, but became temporalily very small (~0.05 mag) on Jan. 14. Further observations by Berto Monard, William Stein, Josch Hambsch, Greg Bolt, Kiyoshi Kasai and Tomohito Ohshima et al. at Kyoto University, showed this dwarf nova started the rapid decline on Jan 15. Since the length for which this object was at the plateau stage was 5 days, the true start of outburst seems to have been a little earlier.

Diego Rodriguez reported that the dwarf nova faded down to 17.13 mag(CR), 17.50 mag(CV), on Jan. 17.93.


(Supplement on June 23, 2013)

Taichi Kato, Kyoto University, et al., published the paper.

PASJ: Publ. Astron. Soc. Japan , 1-?? (Feb. 23, 2013)
Survey of Period Variations of Superhumps in SU UMa-Type Dwarf Novae. IV: The Fourth Year (2011--2012)
T. Kato, et al.

o Recent Observations

(Updated on June 14, 2015)

2014 Apr.  5.898    [18.2   C   Eddy Muyllaert
2014 Mar.  1.994    [17.8   C   Eddy Muyllaert
2014 Feb.  8.038    [17.5   C   Eddy Muyllaert
2012 Mar. 21.56306  [15.3   C   Youichirou Nakashima
2012 Mar. 21.56170  [15.2   C   Youichirou Nakashima
2012 Mar. 21.56035  [14.9   C   Youichirou Nakashima
2012 Feb. 19.59005  [15.6   C   Youichirou Nakashima
2012 Feb. 19.58868  [15.8   C   Youichirou Nakashima
2012 Feb. 19.58733  [15.8   C   Youichirou Nakashima
2012 Feb. 12.59933  [14.1   C   Youichirou Nakashima
2012 Feb. 12.59796  [14.2   C   Youichirou Nakashima
2012 Feb. 12.59661  [14.5   C   Youichirou Nakashima
2012 Feb.  2.65692  [15.5   C   Youichirou Nakashima
2012 Feb.  2.65559  [15.3   C   Youichirou Nakashima
2012 Feb.  2.65425  [15.5   C   Youichirou Nakashima
2012 Jan. 30.64270  [15.6   C   Youichirou Nakashima
2012 Jan. 30.64137  [15.6   C   Youichirou Nakashima
2012 Jan. 30.64002  [15.5   C   Youichirou Nakashima
2012 Jan. 17.932     17.50  CV  Diego Rodriguez
2012 Jan. 17.930     17.13  CR  Diego Rodriguez
2012 Jan. 17.59763  [15.7   C   Youichirou Nakashima
2012 Jan. 17.59628  [15.3   C   Youichirou Nakashima
2012 Jan. 17.59495  [15.6   C   Youichirou Nakashima
2012 Jan.  8.923     14.65  CV  Diego Rodriguez
2012 Jan.  8.919     14.66  CV  Diego Rodriguez
2012 Jan.  5.62720   14.1   C   Youichirou Nakashima
2012 Jan.  5.62586   14.1   C   Youichirou Nakashima
2012 Jan.  5.62451   14.3   C   Youichirou Nakashima
2011 Dec. 24.80741  [14.4   C   Youichirou Nakashima
2011 Dec. 24.80606  [14.5   C   Youichirou Nakashima
2011 Dec. 24.80472  [14.5   C   Youichirou Nakashima
2011 Dec. 24.80339  [14.6   C   Youichirou Nakashima
2011 Nov. 20.77806  [15.5   C   Youichirou Nakashima
2011 Nov. 20.77671  [15.6   C   Youichirou Nakashima
2011 Nov. 20.77538  [15.6   C   Youichirou Nakashima
2011 Mar. 23.54037  [15.6   C   Youichirou Nakashima
2011 Mar. 23.53903  [15.3   C   Youichirou Nakashima
2011 Mar. 23.53770  [15.3   C   Youichirou Nakashima
2011 Jan. 15.77907  [15.3   C   Youichirou Nakashima
2011 Jan. 15.77771  [15.3   C   Youichirou Nakashima
2011 Jan. 15.77634  [15.6   C   Youichirou Nakashima

o Recent Images

(Updated on Feb. 3, 2012)

2012 Jan. 10.965
Luca Buzzi and Federica Luppi

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