SKY SKETCHERS POST MORTEM
By Scott Mellish
Abell 2806
PHOENIX
00 40 10 -56 09 00
Phoenix is one of those constellations that does not have too much in the way of bright objects, but despite this it makes up for the deficiency with a number of fine galaxy clusters of which Abell 2806 is one of the better examples. NGC 215 is the brightest of the cluster members. Some 11’ below this galaxy is a trio of fainter objects starting to the right with the diffuse NGC 212, a featureless smudge about 1.2’ x 1.0’ in size and of around mag 13.0. To the left and slightly below is MAC 0040-5609 a small object only some 0.3’ x 0.3’ in size but visible without averted vision, this galaxy would be about mag 15.0. Another 3’ to the left and slightly above is the small galaxy MAC 0040-5610A. This object had a point like core and a faint outer halo that was only barely visible.
Below these two objects is another faint galaxy MAC 0040-5609, which would be close to mag 16.0. Also of note is yet another galaxy that was barely in the field located some 11’ to the right of NGC 215, this is MAC 0041-5608. It’s listed mag. was 15.0 but it seemed slightly brighter than that, it is another small object at only 1.0’ x 3.0’ in size. Some relatively bright stars also punctuated the field making for a rather satisfying view.
Abell 2731
PHOENIX
00 10 12 -56 59 00
This galaxy cluster occupied a field that almost had more galaxies in it than stars. The dominant member of this collection is NGC 25, a small fuzzy ball of around mag 13.0 and 1.3’ x 1.0’ in size.
Some 5’ above NGC 25 is the diffuse and slightly elongated galaxy Fair 1. This tiny object was only around 0.5’ x 0.3’ in size and relatively faint at about mag 15.7. Starting from NGC 25 and about another 5’ to the right iwe come to a trio of diffuse galaxies, the first object almost directly across from NGC 25 is NGC 28 a much less conspicuous object at mag 14.5 and only some 0.8’ x 0.6’ in size.
To the right of NGC 28 is the featureless NGC 31 that is visually larger at some 1.3’ x 1.0’ in size but only slightly brighter at mag 14.0. Directly above and slightly to the left of both these galaxies is MAC 0010-5700 which viewed as a quite faint object in the eyepiece at 314x magnification.
This was a relatively bright cluster and provided a nice field full of galaxies.
ESO 293-34/MCG-7-1-10
PHOENIX
00 06 20.0 -41 29 36
This pair of galaxies in the 56cm dob at 314x mag made for a rather pleasing view. On my charts ESO 293-34 did not look like anything special but in the eyepiece the galaxy was a rather bright acute edge on system with a much smaller companion just 1’ away. A supernova was discovered in this galaxy in 2009 by Stuart Parker, a New Zealand dairy farmer who has a farm at Oxford, just north of the South island city of Christchurch using a 14-inch telescope. It was located 16" east and 60" north of the centre and reached Mag 15.3.
It was classed as a type IIb which has a weak hydrogen line in its initial spectrum. After the initial peak in its light curve there is a second peak that has a spectrum which more closely resembles a type Ib supernova. The progenitor could have been a giant star which lost most of its hydrogen envelope due to interactions with a companion in a binary system, leaving behind the core that consisted almost entirely of helium. As the ejecta of a Type IIb expands, the hydrogen layer quickly becomes more transparent and reveals the deeper layers.
This galaxy it has a distinct distorted shape, but this feature was not evident in the eyepiece. At roughly mag 13.6 it is not a difficult object, but it is only some 3.1’ x 1.0’ in size, with the smaller and fainter companion just a mere 0.7’ x 0.2’ in size and of mag 15.0. Overall this is an intriguing object with a little bit of history attached to it.
Clear Skies.