Nova remnants?

[Robin]

A happy new year 2021 everyone!

Recently I found an old article in the former German magazine Interstellarum (Interstellarum 08, pp. 21, 03/1996) that deals with visual observations of nova remnants. In addition to exhibiting O-III lines (which novae typically do), some novae leave behind nova shells or nova remnants as expanding non-stellar matter clouds to be seen with O-III or UHC filters.
The author Ronald Stoyan describes Nova Persei 1901 and Nova Herculis 1934 (DQ Her), whose shells he observed with 14" aperture presumably in the 1990s.

Now this was a quarter century ago and I wonder if some of these nova shells can be observed nowadays. Is this something some of you do?
I have never read a visual observing report about nova remnants in an internet forum. If so, which nova shells can be observed nowadays (and how much aperture is needed)?

Some of the brightest novae that happend since then were Nova Aquilae 1999b (V1494 Aql) and Nova Scorpii 2007 (V1280 Sco) that reached 3.9 mag.
According to this paper there is a bipolar nebula around V1280 Sco with less than an arcsecond diameter in 2011 (but must have been expanding since then).
https://www.aanda.org/articles/aa/full_html/2012/09/aa19825-12/aa19825-12.html

This paper shows a few photos of nova shells taken in the 1990s in figure 4:
https://arxiv.org/ftp/astro-ph/papers/0211/0211437.pdf

I can imagine most of these old remnants observed in the 1990s may be too large and faint nowadays. Or perhaps there were only the two nova shells mentioned in the Interstellarum paper visible for amateurs?

Has anyone observed such nebulae in recent years?


Clear skies,

Robin

[Clear Skies]

Hi Robin,

Thank you for posting this! I took a look at the second paper you linked to, and based on DSS imagery only the SNR's around DQ Herculis (https://archive.stsci.edu/cgi-bin/dss_search?v=poss2ukstu_red&r=18+07+30.20&d=%2B45+51+32.0&e=J2000&h=15.0&w=15.0&f=gif&c=none&fov=NONE&v3=) and GK Persei (https://archive.stsci.edu/cgi-bin/dss_search?v=poss2ukstu_red&r=03+31+12.00&d=%2B43+54+16.3&e=J2000&h=15.0&w=15.0&f=gif&c=none&fov=NONE&v3=) appear to be in reach of larger (16"+ ?) amateur scopes.

Both of the SNR's made it into Sven Cederblad's catalog: Cederblad 155 (http://simbad.u-strasbg.fr/simbad/sim-id?Ident=ced+155&submit=submit+id) and 17 (http://simbad.u-strasbg.fr/simbad/sim-id?Ident=ced+17&submit=submit+id), respectively. SIMBAD's coordinates are a bit off. Here's another image (http://www.capella-observatory.com/ImageHTMLs/DiffuseNebula/Ced155.htm) of Cederblad 155.

[Uwe Glahn]

Interesting topic Robin.
I logged three attempts on GK Persei with my 27-inch, all under good to very good transparency. Results were negative on the first two attempts and one suspected pop with 172x + UHC. I saw an extremely faint round glow at the limit of perception and I classify my observation as 60/40 positive. I made no sketch and will try it again with the next larger aperture.

[Robin]

Hi Victor and Uwe,

Thank you for your replies! It is really interesting that GK Per went from visible with 14" to limit of perception with 27" within ~ 2 decades. But probably it could have been expected to be much dimmer now that it has expanded (larger surface and less excitation).

I took a quick look at photos from the Panstarrs survey (newer than DSS) for locations of a few novae that happened a few decades ago, but didn't find any nebulae there.

Clear skies

Robin