[vsnet-alert 24503] Re: ASASSN-20jl - strange 12.8m object in Hercules

[Gianluca Masi]

Dear Denis and All,

I just managed to take a couple of image and I find a source at the following 
end figures:

RA = 14.70s; Decl.= 17.7" (J2000.0)

mag. 13.0 on 31.8422 July 2020 (unfiltered, R-mags for the reference stars from 
the Gaia DR1 star catalogue).

Best
Gianluca Masi
Virtual Telescope Project

Il 31/07/2020 21:25, Denis Denisenko d.v.denisenko at gmail.com via vsnet-alert ha 
scritto:
> ASAS-SN (Shappee et al., 2014; Kochanek et al., 2017) has reported a
> bright, low-amplitude transient in Hercules on July 31:
> 
> ASASSN-20jl
>    20200729.2489  15.010g  ASAS-SN
>    20200729.2502  15.050g  ASAS-SN
>    20200729.2515  15.075g  ASAS-SN
>    20200731.2993  12.844g  ASAS-SN
>    20200731.3006  12.827g  ASAS-SN
>    20200731.3019  12.849g  ASAS-SN
> 
> ASAS-SN light curve for the last 100 days:
> https://asas-sn.osu.edu/light_curves/b149e6ec-6b17-4d74-9f57-cb5d070d9ffb
> 
> Gaia DR2 position: 16 46 14.67 +17 00 17.5
> Plx=1.16(3) mas, pmRA=9.47(3) mas/yr, pmDE=-11.09(3) mas/yr.
> 
> Color-combined DSS finder chart:
> http://scan.sai.msu.ru/~denis/ASASSN-20lj-BRIR.jpg
> 
> IDs from other catalogs:
> 2MASS J16461467+1700175
> GSC 01524-01167
> NSVS 10719460
> SDSS J164614.67+170017.4
> USNO-A2.0 1050-08124731
> USNO-B1.0 1070-0305017
> WISE J164614.68+170017.4
> 
> The star of a kind that shouldn't go into outburst. Neither blue, nor
> particularly red object. No UV excess (V=14.7, NUV=20.8). Gaia absolute
> magnitude M=+4.9, effective temperature 5592+/-54 K (Bai et al., 2019) -
> pretty Sun-like. No sign of the past variability in CRTS, NSVS, ASAS,
> DASCH, ZTF data or on the NEAT images. APASS magnitudes are
> V=14.716+/-0.016, B=15.431+/-0.083. No asteroids or minor planets at this
> position in MPChecker.
> 
> Confirmation from Europe or South Africa is required.
> 
> Denis Denisenko
>