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[vsnet-campaign-nova 106] Re: [vsnet-alert 5493] Possible Nova in Pup
Dear Colleagues,
using an image kindly provided by M. Uemura (Kyoto University) I performed astrometry on
this nova candidate, getting the following results:
R.A.: 07h 37m 56.91s; Decl.: -25d 56' 59.0" (J2000.0)
10 reference stars from USNO A2.0. Mean residuals: 0.22"
USNO A2.0 reports the star A0600.06937901 at
R.A.: 07h 37m 56.88s; Decl.: -25d 56' 59.1" (J2000.0)
m(R)=13.2; B-V=0.6 mag.
Confronting these two positions, the two objects are about 0.5" apart. So, A0600.06937901
actually has good probabilities to be the real progenitor (if this is a nova).
Regards,
Gianluca Masi
Taichi Kato wrote:
>
> Possible Nova in Pup
>
> The accurate position provided by H. Abe agrees the position of a 14-th
> mag USNO star within 1-2 arcsec. If this star is indeed the progenitor
> of the erupting object, the color from the comparison between the visual
> and 2MASS magnitudes becomes V-J = +2. The color is not particularly red
> in this field. Even assuming that the object is not significantly
> reddened, the color is still bluer than most of symbiotic stars, which
> have V-J colors of +3 to +5 or even larger. If the object is a nova, the
> color suggests either a) usual cataclysmic variable with moderate reddening
> or b) cataclysmic-type binary with a relatively evolved secondary.
> [e.g. U Sco (Porb=1.2d) has a V-J color of +1.5].
>
> Regards,
> Taichi Kato
--
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* Gianluca Masi "Two things fill the soul *
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* Center for Backyard Astrophysics - Italy *
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