Single repository for records of nova discoveries

Affiliation
American Association of Variable Star Observers (AAVSO)
Wed, 06/28/2017 - 00:19

Hi All

I find it concerning that there does not now appears to be a single repository for announcing nova discoveries.  Historically they were reported and managed through the IAU CBAT service with IAUC and (more recently) CBET's that announced discoveries.  The CBAT even maintained a historical list of novae (http://www.cbat.eps.harvard.edu/nova_list.html) but I notice that this has not been updated since 2010.

More recently discoveries by the ASASSN team have been reported through ATel.  Not all of these are being picked up via the IAU CBAT.  The recent nova in Centaurus (ASASSN-17gk) is a case in point.  This has been observed now for quite a while and has not been recognised as such by the IAU CBAT.

I don't know if others have a similar concern as me.  Obviously our very own VSX is playing a very important role here in that it is picking up all novae discoveries, however it is unfortunate that we seem to be losing that historical link with the IAU CBAT with these other channels now somewhat fragmented.

On a related matter, some suspected nova discooveries have slipped through the cracks due to lack of followup observations, notably spectroscopy, to confirm exact nature of these nova candidates.  A case in point is a suspect discovered by Nick Brown (incidently from my home town!) in Carina back in July 2012 (PNV J09410000-5759540).  Nick reported it to the IAU CBAT and if you look at the light curve based on observations in the AID, it's quite likely that this was a nova.  However with no spectra taken, it was never confirmed and officially designated as a nova.  This is troubling for future researchers who may wish to study statistics on novae within the Milky Way and the like.

Regards

Andrew

Affiliation
American Association of Variable Star Observers (AAVSO)
Nova Discovery Reports and List

Hi Andrew,

I agree with you in general, we need timely announcements of nova discoveries through a single channel.

In terms of nova lists: I've been maintaining my own list of recent Galactic nova for my own purposes (https://asd.gsfc.nasa.gov/Koji.Mukai/novae/novae.html) and Bill Gray has a complete list of old and new Galactic novae (https://projectpluto.com/galnovae/galnovae.htm) but both are secondary sources, in that these list contain objects that had been announced elsewhere.

As for ASASSN-17gk (and ASASSN-17hx): I wonder if ASASSN folks have notified CBAT of their discovery, or if they think publishing ATels is enough (I believe it's not sufficient). It's also possible that the CBAT is aware of these discoveries, but haven't gotten around to issuing a CBET. (They usually are very prompt about putting objects on their transient confirmation page, but they may consider these to be confirmed already.)

One other thought: whoever is going to be the gatekeeper, I hope there will be a transparent standard for when a nova is considered confirmed, lleaving room for "candidate nova" category.

- Koji Mukai