by Joe Fragola
| Location | Home Driveway, San Jose, CA |
|---|---|
| Date/Time | 27 July 2003 21:33 - 28 July 2003 00:45 PDT (28 July 2003 04:33 - 07:45 UT) |
| Sky Conditions | Clear, limiting visual magnitude approx. 4.0 No Moon |
| Equipment | Orion XT10 Dobsonian |
I had hoped to make it out to my favorite nearby “dark sky” site, Coyote Lake Park, on Saturday. But after a full day in the sun while attending my kid’s swim team league championships I was sapped. I didn’t make it out at all Saturday night, and with a busy Monday of work looming, I had to settle for a Sunday night of observing from my driveway at home. I was anxious to continue my “formal” Messier survey for the Astronomical League’s Messier Observing Club certificate and pin. My targets for the evening consisted of the remaining objects on the Messier list located in the Ophiuchus/Sagittarius region. This included three open clusters and three globulars. I ended up observing only five of the six targets (I skipped M54 for now).
Here’s the list of objects that I recorded.....
All objects were viewed with a 25mm Plossl (50x) and a 12.5mm Plossl (100x) (Note: FOV = field-of-view)
M19 (globular cluster); Ophiuchus - this was a relatively small, faint glob.; the fact that my view was across the roof of a neighbor’s house didn’t help matters; there was not much resolution of individual stars at magnifications of 50x or 100x; the view through the 12.5mm Plossl showed a brighter core, but it was still hard to resolve stars toward the edge of the globular; I have this one marked for a re-visit from darker skies.
M26 (open star cluster); Scutum - open clusters are not at the top of my “favorite object” list; this open cluster was pretty sparse; with the higher magnification of the 12.5mm eyepiece (100x) I was able to resolve a small diamond asterism formed by the brightest four stars near the center of the cluster; I also noted a small right triangle of stars to the NW of this unimpressive Messier object.
M25 (open star cluster); Sagittarius - compared to the last target, this was a rich open star cluster; stars spread out to fill the 25mm FOV; there are a lot of bright stars in this star cluster; at 100x the cluster spreads out beyond the FOV; maybe open clusters aren’t so bad after all.
M23 (open star cluster); Sagittarius - OK, well that was quick - I’m back to not liking open clusters again; this one has fairly faint members that do not fill the FOV of the 25mm Plossl (50x); there is a 6.5 magnitude star in the same FOV (HIP 87782); at 100x this cluster spreads out a bit, but still does not quite fill the FOV; at this higher magnification, the stars in the cluster can be seen to form several arching rows.
M28 (globular cluster); Sagittarius - an easy target to find - close to lambda Sagittarii which marks the top of the “teapot” lid; this object appeared as a small, compact globular at 50x; when increasing the magnification to 100x, I was able to detect a brighter core with a fainter halo of stars; since I like globulars, this one should be re-observed from darker skies.
Mars - It was past Midnight now (00:15 a.m. PDT/ 07:15 UT). I noticed that Mars had started to rise in the SE. Even though the location wasn’t ideal (viewing across a neighbor’s roof), I had to have a look. The views were very unstable with only a second or two of steady viewing at a time. I could easily see the bright, white south polar ice cap. The color of the Martian disk was a pale orange or peach. During the short instances of steady seeing I could also make out some bluish-gray surface markings. I viewed Mars at magnifications of 100x and 200x (12.5mm Plossl in combination with and without the 2x Barlow). The views were better at 200x, but very unsteady. There’s still a month before Mars reaches opposition, so I’m hoping for steadier views in the future.
It was a short, but productive evening with 5 “new” Messier objects observed. This brings my Messier list total to 40 - about 36% completed now. I can still pick up a few more Summer objects in the early evenings in Sagittarius (M54), Lyra (M56), Cygnus (M29 and M39), Vulpecula (M27), and Sagitta (M71). Then I’ll have to wait until the group of Autumn Messier objects becomes more prominent.