Abell 10
Also known as K 1-7
RA: 05h 31.763m
Dec: +06° 55.95' (2000)
Mag: 15.2 (P)
Size: 34.0"
Mag C. Star: 20.2
The list of planetary nebulae published by George Abell in 1966 in his paper on the
Properties of Old Planetary Nebulae has become the holy grail for many observers
of these objects, once the errors and misidentifications have been taken out. Many
of these planetary nebulae are extremely challenging and questionably visible. Orion
contains five objects listed in the Abell catalogue in Abell 10, 11, 12, 13 and 14. Of
these Abell 12 is often covered, although perhaps surprisingly not yet as an OOTW
whilst Abell 11 has been reclassified as a reflection nebula. Of the other 3 only
Abell 10 has been observed reliably. It is actually quite a bright nebula as Abell
planetaries go and it is sometimes referred to as by the name Kohoutek 1-7 as
Lubos Kohoutek was actually the first person to discover it in 1963. This name confusion
can provide some challenges when searching out information on it, and this is perhaps
one of the reasons for it not being as well-known as Abell 12. Distance estimates, as
often for planetary nebulae, are widely variable but Abell 10 is thought to be perhaps 4
kpc away with a large uncertainty. Abell 10 is of interest when studying the chemical
evolution of our galaxy because being almost in the galactic anti-centre position, we can
see how the chemical makeup of the outer parts of the galaxy has evolved. Visually Abell 10
appears as a bright disk and although there is some structure seen internally and the outer
edge seems discontinuous on deep images this is unlikely to be seen visually except with large
telescopes. It appears that Abell 10 is starting to interact with the local ISM which may be
what is giving rise to some of the edge structures. There are not that many good deep
images of Abell 10, even the Hubble archive contains none. This is one of the few I have found http://bte999.jalbum.net/Other%20Ima...II%20crop.html.
Abell 10 does show up strongly in some of the WISE infrared passbands which suggests it contains
a lot of dust. The nebula also shows up weakly in the UV, although its central star is very bright
in those wavelengths, which suggests it is very hot. It will be best seen with an OIII filter at low
to medium powers and perhaps a UHC type filter at higher powers. I have seen it with difficulty
with my 38cm telescope and pretty easily with a 55cm telescope from the UK. There are suggestions
from high altitude sites it may be visible in apertures as small as 20cm with a filter. I think the magnitude
given, which is a photographic one, is vastly fainter than the object actually appears to be visually. There is a
drawing in the recently published Interstellarum Deep Sky Guide which suggests that this may be a target for 12"
telescopes
abell10_dss1.jpg
As always give it a go and let us know. This is of course the last OOTW for 2019 and indeed the last one of the decade.
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