Affiliation
Association Française des Observateurs d'Étoiles Variables (AFOEV)
Thu, 05/18/2017 - 03:14
ASASSN-17gk (N:)
RA 13:20:55.32, DEC -63:42:18.5 (J2000.0)
K. Z. Stanek et al.:
"ASAS-SN Discovery of A Likely Galactic Nova ASASSN-17gk on the Rise" (ATel #10387)
http://www.astronomerstelegram.org/?read=10387
ASASSN-17gk 20170423.16 <174V ASN
ASASSN-17gk 20170425.08 133V ASN
ASASSN-17gk 20170428.11 116V ASN
ASASSN-17gk 20170504.19 12.05V ASN
ASASSN-17gk 20170517.28 109V ASN
A Gaia DR1 source (G= 18.767 mag) is located at RA 13:20:55.334, DEC -63:42:19.16 (J2000.0), 0.7" from the reported position of the transient.
Clear skies,
Patrick
PS:
Quote from ATel #10387:
"Follow-up observations, especially multi-band photometry and spectroscopy, are strongly encouraged."
First spectrum attached (non instrument corrected).
ASASSN-17gk now has a sequence
Ad Astra & Good Observing,
Tim Crawford, CTX, Sequence Team
After grabbing the confirmation spectra, I managed very quick V-band and B-band images before the cloud (and rain) hit Perth last night. I'm not convinced my tranformations are perfect, as the magnitude (V=8.8) came out at much brighter than PEX's visual observation not far from me last night. See the database for information. I couldn't get TA to work (I suspect it doesn't like ASASSN-17gk as the database reference) so relied on manual (ie, spreadsheet) transformaiton. I suspect that, together with noisey data, may be at play. For the mean time, I figure some photometry is better than none.
EDIT: I've tried replacing ASASSN-17gk with 000-BMH-424 in TA without success. The complaint is "no CREF available, possibly bad char reference, failed VSP API chart request, etc.".
EDIT 2: I've fixed my issues (error with reporting of instrumental values from Muniwin) and recomputed.
Corrected transformed CCD measurements:
V = 10.70
B = 11.78
Database updated accordingly.
Paul
AAVSO Alert Notice 578 announces and summarizes information on ASASSN-17gk, a galactic nova in Centaurus. Please see the Alert Notice for details and observing instructions.
Many thanks, and good observing,
Elizabeth Waagen, AAVSO HQ
I have tried to take a high resolution spectra of the Ha region of this nova. At mag V=11 at the time it is very dim for my setup. A low res spectrum is easy but I didn't have the low res spectrograph on the scope at the time.
I was able to identify the Ha emission and measure the expansion velocity at 1000km/s despite a low S/N with just 15 mins of exposure.
Terry