Object of the Week August 4, 2013 - NGC 7252 and the littlest Voorwerpje

NGC 7252 AKA Arp 226

Aquarius

RA
22 20 44

Dec
-24 40 42

Mag 12.1 V

Type (R)SA(r)

This is a famous galaxy in the late stages of recovery from a merger - NGC 7252, also known as the "Atoms for Peace" galaxy after a resemblance to a 1960s-era logo. It is also in the Arps catalog of peculiar galaxies as #226 "Amorphous spiral arms". It has listed in NED 247 references so this is one well studied galaxy. I have viewed this galaxy many times over the years and must say that the long tidal tails that show up well in images are hard to see visually.

Attachment 801

Francois Schweizer of the Carnegie Observatories and Pat Seitzer of the University of Michigan have studied NGC 7252 off and on for 20 years. In a new paper, they and additional colleagues Danial Kelson, Edward Villanueva, and Gregory Walth report a new facet of this system - it hosts the Littlest Voorwerpje (so far). Link to paper http://arxiv.org/abs/1307.2233

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This new O III object looked fairly bright on the DSS so I thought I would give it a go this week. I viewed it twice this week @ 697 X the O III cloud was easy to see at this power but the knot near the end (little Hanny) was tough to see. I tried a O III but it darked the field to much. I then tried a Sloan G filter which works well on "Hanny's Voowearp"and had no response to this filter. Not deterred I then tried a DGM galaxy contrast filter which works well on some H II knots in other galaxies. This filter worked great on"little Hanny's" it really lit it up! It looked like a dim star blinking in and out with the seeing. As with other objects once I saw "little Hanny" I could see its faint glow unfiltered in moments of steady seeing. This is a object that has just been released so if you want to be one of the first to see it visually" Give it a Go"

There is another object that is a real challenge associated with NGC 7252 that is the star clusters W-3 it is a cluster that I have read is 100 times larger than our globular clusters which some think it is a UCD or the striped out core of a dwarf galaxy that has merged with NGC 7252. I know of no visual observations of this object so you could be the first if you can catch it!

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So here are some real challenging object for you deep sky hounds so as always,

“Give it a go and let us know!”

Good luck and great viewing!

Hi Jim

Thank you for the interesting presentation of this object!!
IT`s a new object for me and i hope for a good observation next weekend.
The HII region "Little Hanny" is really a big challenge!!
I try the galaxy with my 16" telescope and look what goes.
Your observation with the Sloane G Filter is very interesting!!
I did not know this filter!!

Regards from germany
Hajü
www.astromerk.de

Hi Haju,

The Sloan filters are photometric filters that were used on the Sloan telescope for the Sloan survey. This is a link that shows the band pass of the filter http://www.astrodon.com/products/fil...trics_-_sloan/

Dr William Keel who is the lead astronomer on Hanny's Voorwerp suggested to me to try the Sloan G on Hanny's, he thought from the spectrometry on the object that the slow G would enhance the visual view of this unusual object. He was right this filter lights up this small and unusual object. Like I posted above the Sloan G filter had little to no response on the Little Hanny's object in NGC 7252.

Interesting object. Funny name... I see the use of Dutch in astronomy is expanding; it's becoming advanced ;)