SSPM18. November New Moon at Wiruna ...

By Scott Mellish, 1999

The November new moon weekend at Wiruna proved to be a mixed bag as far as the weather went, with the regular cloud hanging about till around midnight when it would mysteriously disappear without a trace. This odd phenomenon occurred three nights in a row, which was a bit of a turn up for the books, as it was looking pretty grim there for a while. Especially as Mick McCullagh had his new 18-inch scope up and running after many months of painstaking construction.

So the observing was done from midnight onwards after most of us spent the early part of the nights either sleeping or just sitting around talking.

For those who slept like myself, it was pretty hard to get out of bed. But once up and observing it was nigh on impossible to go back to sleep with a perfectly clear sky overhead.

I took the opportunity to arouse Mick from his slumber, as a fine l8inch scope was there waiting to get some use. Though Mick did not bounce too quickly out of bed, he was soon inclined to do so as a steady flow of eager individuals constantly harassed him within his nylon abode. Alas Mick finally presented himself upon the observing field to be greeted by a group of avid observers waiting to get their first view through the new scope. I was eager to have a look through it myself, but would wait till later on. For the moment I planned to rummage through the constellation of Cetus and have a look for some of the many galaxies that abound within this region of the sky.

To start with I came across a very interesting little group of galaxies consisting of NGC 543/547/545/541/535 and UGC 1003, NGC 541 is also listed as Arp 133 which gives it an air of strangeness about it. No doubt some kind of active galaxy of some type or other. If you look at the mega star field you can see plotted over NGC 541 the galaxy MAC 0125-0122B. This may be interacting with 541, or simply be a foreground galaxy-or one much more distant.

As you can see in Sketch 1, there are six relatively compact little galaxies of around 12-13 mag. This is a most interesting group, with the close pair making the centrepiece of the display. At the top of the field is NGC 543 a tiny featureless object of about 13th' mag that has a core region of some form though it is not a definitive feature. Below this object is the far more interesting pair consisting of NGC 547/545. This undoubtedly interacting pair is the centrepiece of the group and also the brightest at around l2th mag. In the l6inch at 210x this pair is easily separated, and a soft diffuse halo surrounds them. A very interesting little pair that are quite a treat to look at.

Some 5 arc secs to the left of field is the curious NGC 541, this galaxy is most likely of some peculiar type and may have an interacting companion. It is also known as Minkowski's object whatever that may mean and is not anything particularly special in the eyepiece at 210x mag. It is at about l3th, round, and slightly brighter towards the middle. I will certainly be digging up some information on this object to satisfy my curiosity as to what exactly is happening with it.

If you look at the accompanying megastar field you can also see plotted with NGC 541 the galaxy MAC 0126-022B. This object may be a companion to 541, or just simply a galaxy much farther away. In any case I did not see this object in the l6inch, nor was I aware of it until I checked the field via megastar.

About 5' to the¿sw lies NGC 535 another almost identical object of about l2th mag. This tiny little galaxy is slightly larger than 531 and just a touch brighter. There is little to no halo present and it is very compressed in appearance.

Below NGC 535 at about 6arc secs to the south east lies UGC 1003. Another almost clone of the preceding few. At around 13th mag 1003 fits in well with the overall group, however it seems a bit detached due to its position.1003 with averted vision does sport a very faint and ghostly outer halo, however it is extremely diffuse.

This rather quaint and interesting grouping of galaxies is highly recommended.

With sketch 2, we travel to Orion to have a look at a planetary nebula. NGC 2022 is a pleasant, easy to observe object of around 12th mag. I did not use an OIII filter on this object, preferring to observe it as is. The overall appearance of this object is of a compressed and bright smudge, with tatty edges if you look closely.

According to megastar, the central star of this object is at 15.8 mag so this would make it very difficult to see visually. In any case I did not even bother. Preferring to just observe this interesting planetary on its own. NGC 2022 is about 19.0 arc secs in size.

To round off this edition of post mortem we now travel back to Cetus from whence we came. Sketch 3 shows a typical bright-elongated galaxy of about 11th mag. It is a bit of a change from the usual small, faint and featureless smudges as it is elongated and almost forming the classic cigar shape so often seen. Crossing the centre of this object is a wispy streak that can been seen better with averted vision. It is diffuse and I would suggest that it is a spiral arm crossing the line of sight. Overall this was another treat to observe and if you look at the accompanying megastar chart of the region you can see that there is two other galaxies in the field which those with larger scopes can try to observe, though I did not know of their existence until I got home and printed out the chart. Suffice to say I will no doubt be calling back for a return visit.

Clear Skies.