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A Tale of Two Asterisms

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9 years 11 months ago #102584 by mykc
A Tale of Two Asterisms was created by mykc
While observing double stars over the last few months, I came across a couple of little known asterisms that are worth a look.

I noticed the first when observing ES 42, aka ADS310 (RA 00:22:52, Dec +54:17:54, magnitudes 8.4 & 9.4, separation 7"). This double consists of a golden-orange primary, with a tiny speck very close beside it at 50X. It is not particularly interesting, but what caught my eye was that it was the central star of an obvious W-shaped asterism of relatively faint, but quite distinct, stars in a rich field. The asterism is another "little Cassopeia", quite a good likeness of the original, located within the 'parent' constellation. A search revealed that it was recorded by the Brazilian amateur Bruno Sampaio Alessi, and is listed in the Deep Sky Hunter's list of asterisms as Alessi J0022.7+5417. However, Jaakko Saloranto, a Finnish amateur well known for his observations and sketches of deep sky objects, has suggested ( fdsa-blog.blogspot.ie/2013/08/johann-bod...ee-lost-objects.html ) that this asterism was originally noted by Johann Bode and included in a list of 75 objects in 1777 in the "Astronomisches Jahrbuch". Interestingly, he suggests that, around 1782, Bode also discovered the famous "Little Queen" asterism in Draco that is often referred to as Kemble 2 ( www.deep-sky.co.uk/asterisms.htm ).

A second asterism suggested itself while observing STF 2896 (RA 22:18:28, Dec +63:13:22, magnitudes 7.8 & 8.6, separation 21"). This is a nice pair of yellowish stars, mildly unequal and well separated at 50X. In my first observation in 2012 I noted that it was at one corner of a triangle made up of several faint stars, that looked like a small cluster. In more recent observations using a larger aperture (280mm) I noticed that several other faint stars form a line that extends one side of the triangle in both directions, forming a 'witch's hat' asterism. The witch's hat shape is quite distinct, though the stars making up the eastern end of the brim are very faint. The relatively bright stars of the double look like baleful eyes just below the 'brim' of the hat. As far as I know, this shape has not been pointed out previously.

Of course the human mind is very adept at joining stellar dots to form shapes in the sky, and such asterisms are numerous and of no significance. Nevertheless, they are fun to observe and to search for. I try always to look at the field surrounding the targets I am observing in the hope of spotting nice patterns. I would be very interested to know if any others see the "little Cassopeia" and the "witch's hat", with their inhabitant doubles. They are rather faint but should be oservable with medium sized scopes, and I would be delighted to hear of other observations.

Thanks for reading, Mike.

Skywatcher 120 mm ED on a CG5 mount.
Orion UK 300mm Dobsonian
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9 years 11 months ago #102585 by mykc
Replied by mykc on topic A Tale of Two Asterisms
Further rooting on the web reveals that the asterism I called the "witch's hat", which is in Cepheus btw, is more properly known as open cluster Pismis-Moreno 1, sometimes also called the sailboat cluster. The following link includes a DSS image: www.univie.ac.at/webda/cgi-bin/ocl_page.cgi?dirname=pimo01 . The accompanying cluster chart ( www.univie.ac.at/webda/cgi-bin/chart_frame.cgi?pimo01 ) shows why I saw a witch's hat.

Cheers,
Mike

Skywatcher 120 mm ED on a CG5 mount.
Orion UK 300mm Dobsonian

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9 years 11 months ago #102600 by flt158
Replied by flt158 on topic A Tale of Two Asterisms
Hi Mike. I seem to remember back in the 1990's in a Sky and Telescope magazine the mention of a mini Cassiopeia shaped asterism in the constellation of Draco. Is that the one you observed recently? Well done if it is! I looked for it at the time, but could not locate it.

Aubrey.

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9 years 11 months ago #102601 by mykc
Replied by mykc on topic A Tale of Two Asterisms
Hi Aubrey. The "mini Cassopeia" in Draco is the one usually referred to as Kemble 2. It is a remarkably good facsimile of the W-asterism of Cassiopeia and is well worth seeking out (check the link in my original post for details). The one I stumbled upon in not quite such a good likeness, and is located in Cassiopeia. I think both would be readily observable in your 152mm scope. The "witch's hat" includes some fainter stars, so I would be very interested to hear how it appears in other scopes.
With thanks, Mike.

Skywatcher 120 mm ED on a CG5 mount.
Orion UK 300mm Dobsonian
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9 years 11 months ago - 9 years 11 months ago #102615 by stevie
Replied by stevie on topic A Tale of Two Asterisms
Excellent report Mike

Kemble 2 is an nice asterism, and even has a star in approximately the same place as the famous double star eta Cass in the real Cassiopeia.

My favourite is the Klingon battlecruiser, NGC1662, which was first shown to me by Jonathan a couple of years ago. There is an image of this in Mike's "deep sky asterism's" link above.

I remember finding the Toadstool a few years ago at Bragan, but everyone else was having their tea and sandwiches at the time, and weren't particularly interested
Last edit: 9 years 11 months ago by stevie.
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9 years 11 months ago #102618 by flt158
Replied by flt158 on topic A Tale of Two Asterisms
Oh Yeah, I remember the Toadstool asterism. It is in Delphinus.

Aubrey.

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