1 Attachment(s)
Object of the Week January 8th, 2023 - Abell 8
Abell 8
PN G167.0-00.9
Planetary Nebula
Auriga
R.A. 05h06m38.4s
Dec. +39°08'11"
Size 1’
Magnitude: 16.60
CSPN mag 19.7
After the inclusion of the planetary nebula Abell 7 in Lepus a week or so ago as the OOTW
I thought it would be interesting to have a challenge object for more northerly observers.
The planetary nebula now known as Abell 8 was first reported in George Abell’s 1955
paper where it was listed as number 7. In the better known 1966 paper it was renumbered
as Abell 8 which is how it is known today. There have been suggestions that Abell 8 is a
member of the sparse open cluster Bica 6 but there seems little follow up evidence on
this and clusters containing planetary nebulae are not common so I would have thought
if this linkage was secure there would be more information on it. If it is indeed a
member of the cluster, which is thought to be about a billion years old, then the
progenitor of Abell 8 was likely a star in the 2.5 solar mass range. Abell 8 is a relatively
old PN and has a fairly simple structure. The outer ring is very strong in H-Alpha
emission and the interior mostly shines in the light of OIII, however the IPHAS data
does show some structure in the H-Alpha band in the centre. Abell 8 is suggested to
be about 1.6 kpc from us, although the GAIA distance is nearer 2.0 kpc. The PN is
located in the anti-galactic centre location. There is some associated H-Alpha emission
nebulosity in the general area but this is not associated with the PN per-se but it is
likely to be the local ISM excited by UV radiation leaking from the PN, see
https://www.hansonastronomy.com/abell-8 . Otherwise there does not seem to be
much research published on this object.
Attachment 4997
Observationally Abell 8 is going to be a challenge and my only observation of it was
with a 20” and an OIII filter which suggested that it was very faint disk, although
visible with direct vision. The site I observed it from was in Devon in the SW of the
UK so it is not a high altitude site, although transparent by UK standards. Alvin
Huey suggests a similar observation with his 30” and Kent Wallace also suggests a
faint disk with his 20” and an OIII filter. Uwe has some information on his
observations of it as well at http://www.deepsky-visuell.de/
And as always,
“Give it a go and let us know!”
