Monday was a good night for edge-on spirals. This one may be host to a couple embedded satellites, or not...
NGC 4244 – yet another “Silver Needle” – edge on spiral galaxy in Canes Venatici:
Annals of the Deep Sky, vol. 3 features this galaxy on pp. 154-158. The galaxy is unusual for a few reasons: Until recently (2011) it was believed that it did not have a thick disk when it was convention that all spirals do. Data from the Spitzer Telescope detected a subtle thick disk, but only on the near side of the galaxy. NGC 4244 lacks a central bulge, although deep imaging shows a flattened sphere of young stars inside a larger sphere of old stars in the central 32 LY. I did not find NGC 4244 in the Flat Galaxy catalogues, but it should be there. Another oddity is the presence of two irregular HII regions at either tip of the halo, along with a warping at the southern end. SIMBAD identifies these as galaxies, the region at the NE tip classified as Wolf-Rayet galaxy 415; the one to the SW an emission-line galaxy – HS 1214+3801. As expected, there is an ongoing debate concerning the nature of these two regions, with the competing view being that these are simply HII regions associated with NGC 4244 itself. Pretty Deep Maps shows the regions with PGC designations.
NGC 4244 belongs to the M94 group, or Canes Venatici I group, near our Local Group, at a distance of 14 MLY. I was intrigued to see if I could observe the two regions in question.
Observing: No problem finding this one both for star field arrangement and the fact that the galaxy itself is rather bright at mag 10.5/SB 22.3. The Silver Needle moniker is well-earned as the halo appears quite flat at 9.1’ x 1.0’, PA 45°. The core is a central glow that extends for 3.5’ of that length, dropping off in intensity rather quickly. Over time a nearly stellar nucleus would wink out. No dust lane was seen, nor did I expect to see it as it’s quite subtle even in long exposure images. The brighter regions at the two ends took a good bit of time under the hood to finally see, but once spotted they persisted. The warping of the southwest tip was not seen. That feature is likely only observable in long exposure images. Mel?
There are abundant sources for new targets, but Annals of the Deep Sky provides in-depth descriptions of so many it’s become one that I pull down regularly. It’s very convenient to have the research on these objects so easily retrievable.
Sketching: White pastel pencils and white pastel powder on Canson 92 lb. black multimedia paper. 5/8” flat brush for the central halo with a 20/0 mini fan brush finishing the ends. A 10/0 mini Filbert did the central core.
Click to enlarge
-b
Edited by bphaneuf, 20 March 2025 - 09:44 PM.
