Galaxy NGC 4725.
Posted 25 April 2011 - 03:17 AM
Posted 25 April 2011 - 06:25 AM
Posted 25 April 2011 - 10:27 AM
Posted 25 April 2011 - 02:15 PM
@Jef: I don't sketch deep sky objects very often because it is easy to describe it with words - at least most of them. This one required a sketch.
Posted 26 April 2011 - 02:16 PM
Excellent sketch. Your sky at the time of the sketch must have been very good.
Posted 26 April 2011 - 11:56 PM
I enjoy the detail that you pulled out despite the poor seeing conditions. Thanks for sharing it.
Posted 27 April 2011 - 12:55 AM
An excellent observation of NGC 4725 in Coma Berenices. This is an interesting intermediate barred spiral galaxy. I hope to be able to observe it soon. Thank you for sharing it with us all.
Posted 27 April 2011 - 09:27 PM
Your sketch made me to look carefully again at the POSS photo in O'Meara's Herschel 400 Guide, and I saw something that I surely missed in the dim red light on the field: This galaxy actually has a single arm spiraling out from a ring! It is not in the Arp catalog... apparently this is not peculiar enough. The de Vaucouleurs Atlas notes that this galaxy "has the largest inner ring (in terms of angular size) in the sky." The description that follows identifies the two brightest arcs in your sketch as the regions of intense star formation in the ring near the ends of the bar and confirms that a single arm spirals out from the ring.
I particularly like how your sketch captures the inward deviation of the eastern end of the southwestern arc. This is the imperfection of the ring-arm structure that is immediately noticeable in the photographs (the ring is split there like a key ring), but the Atlas does not comment on it. It looks consistent with the presumably clockwise rotation of the arm outside the ring.
Again, a most inspiring sketch, Uwe.
Posted 01 May 2011 - 08:20 AM
A really fine sketch.