"ASAS-SN Discovery of A Likely Galactic Nova ASASSN-16kt at V=9.1" (ATel #9538, #9539)
RA 15:29:01.82, DEC -44:49:40.89 (J2000.0)
Gal l 330.091°, b 9.569°
"ASASSN-16kt was discovered in images obtained on 2016-09-24.00 at V~9.1. We do not detect (V>17.5) the object in images taken on UT 2016-09-20.01 and before. No previous outbursts are detected at this location since ASAS-SN started observing all of the Galactic plane in March 2016."
The following progenitor candidate (19 mag) is 1" from the reported position of the probable nova:
- GSC 2.3 S9CP023399
RA 15 29 01.824, DEC -44 49 39.51 (J2000.0)
F= 18.81, j= 21.62 mag
- Gaia DR1 #5999691733347769472
RA 15 29 01.771, DEC -44 49 39.99 (J2000.0)
G= 18.950 mag
I took a very noisy spectrum tonight as it went behind trees. I also got a single 5 sec V image before it went behind the trees. It is now mag V= 6.83 so has brightened considerably.
The spectrum is below. It is quite noisy but does show Ha emission so is probably an early nova.
Half an ahour ago I estimated it at V= 6.3.
The AAVSO sequence for this bright nova has been updated so we can follow it at this stage (comp stars from 4.8 to 8.6 were added).
** Observers should make an AB scale chart in order to include all comp stars in the field of view **
I'm working with a collaboration of observers and theorists to test a recent theoretical prediction of Ken Shen's---that novae should show fast periodic oscillations in their optical light curves, if gravity waves help expel the envelope.
I'm wondering if any of you have access to a high-speed photometer (Say a photo-multiplier tube) and could observe this target for an hour or two? even exposure times as long as 1 second would be useful, although several exposures per second would be better.
Hi Laura, I am in France and regretfully I can't observe this interesting novae ! There is no problem for a CCD or a DSLR to observe a 6~7 mag star in 1 sec exposure or less using a large enough telescope. It should need only a 12" or so at 1 sec to obtain an high SNR measurement. I am an old electron-optics engineer and I don't think our old PMT friend could help. The true issue is the atmospheric scintillation, it would add a lot of scatter to the result in a so short period. What is the expected amplitude of the oscillation, its frequency, is such frequency more or less stable ? Maybe possible to extract the oscillation from the scatter using wavelet or so ?
Clear Skies !
I made a visual estimate of the nova at magnitude 6.7 tonight.
The weather is expected to deteriorate mid-week, but I will make observations as often as I can.
Thanks to Greg Bolt and his marvelous attention to BSM_Berry, we've been able to get BVRI imagery of the nova. I've posted the results from 160928; I think there is data from 160929 as well that I'll try to submit over the weekend.
BVI are ok in this dataset; R may be lightly saturated (forgot to adjust the exposure for the expected Halpha bump). As the visual observers are showing, this nova is fading quickly. Note that every nova is different from the rest of the group, so this one may continue to fade, or may rebrighten. Keep monitoring until solar conjunction and see what happens!