Henry Coe 06/28/03

by Bob Czerwinski

If I counted correctly, I was one of nine folk who set up one or more 'scopes under clear skies at Henry Coe State Park Saturday evening. We were joined by a few folk visiting the park, so the early part of the evening was mostly social/educational, with the standard run of summertime showcase items offered to our guests. At least one amateur was set up to do imaging, but most of us were just there for observational astronomy.

ObserverBob Czerwinski
DateJune 28-29, 2003
Observing Time9:15pm to 3:10am PDT (UT -7, or 0430-1030, 29 June 2003 UT)
LocationHenry Coe State Park, Approx. 37°11'N 121°30'W, El. ~2600-feet
MoonNew Moon, ~29-days-old, 9:00pm set time
Equipment18" f/4.3 Newt/Dob e/w Telrad and Paracorr
Eyepieces17mm-133x (default) & 12mm-188x TV T4 Nagler; 31mm-73x TV T5 Nagler; 8mm-283x TV Radian (magnifications include Paracorr)
FiltersLumicom OIII
Sky ConditionsZenith LM 6.3; transparency 9/10; seeing ~7-8/10 to start, 9/10 by the end of astronomical twilight
Temp/R.H.All night: 68-72F/22-24%
CommentsLight onshore breeze on and off during the evening; occasional gusts would shake/move the 'scope. Very dry conditions. Although the temperature never dropped below 68F, the occasional breeze made it feel more like the low to mid 60s at times. Clear Sky Clock prediction fairly accurate.

Although the seeing started off just a tad soft, Matthew Marcus still provided an easy split of the Double-Double in his C8, even when the sky was still in twilight mode. By the time astronomical twilight ended, the seeing was very good. A slight onshore breeze was evident throughout the night, one of the things many of us have come to expect when observing from Henry Coe. From time to time our 'scopes would shake and/or wind-vane a little, but in general the breeze was not a big problem. Well, at least not for visual work. Temperatures were very mild, still at 68F when I took my last temperature reading at 3:30am. Fog tried to work its way into the area, but with the exception of a couple tendrils sneaking into the area just south of Gilroy proper, the lights of the Silicon Valley, Morgan Hill and Gilroy were still there in all their ... er, glory.

For the first part of the evening, globs, planetaries, open clusters and nebula (mostly Messier objects) were shown to the public, along with a number of showcase double/multiple stars (e.g., Epsilon Lyra, Alberio, Alcor-Mizar and Polaris), and a few of the brighter galaxies (e.g., M31/32/110, M81/82 and M51). Everybody seemed to enjoy the show. The Veil (the NGC 6960 & 6992/95 portions) was definitely a hit as well, especially with the 31mm/OIII filter combination.

Marching through Hercules.

Following the public show, I spent the rest of the night hunting galaxies in Hercules. Most of these items were spotted using a 17mm eyepiece.

NGC 6073My first target of the night. Didn't take me too long to get to this galaxy as it's on a relatively straight line out from Beta and Gamma Herculis. TheSky says mag 14.2, but it was definitely brighter than this visually, maybe by 0.5-magnitude. Faint, small and oval'ish; not that difficult to find. Don't know why I missed this before, especially when you consider that it's less than 2-degrees from downtown Abell 2151.
NGC 6160A star-hop from Sigma- to 30-Herculis to 6160. TheSky says mag 14.2, and it appears fairly dim, a faint patch of round diffuse light with a low surface brightness with a slight core brightening. (Actually had this logged from Lassen with my 14.5" Newt/Dob, but didn't realize it 'til I started working on my logs Sunday afternoon.)
NGC 6145/6146/6147Hit 6146 first, round, relatively bright with a tiny core, just on the other side of the eyepiece field from 6160, with a 7th magnitude star just a quarter of a degree away. Nearby 6145 was just a faint patch of averted-vision light, maybe a bit oval'ish, just NW of 6146, but without any core I could detect. 6147... well, I'm not certain about this one. TheSky reportedly shows where 6147 is located (just SW of 6146), but after a half-hour of frustration, moving eyepieces back and forth, the only thing I suspected was the coming and going of a tiny faint object, in line with 6146 and 6145, about two-thirds of the way from 6146 to 6145. Visible 10% of the time at best, but definitely there. Is this 6147? TheSky also shows 6141 just NW of 6146, but I saw nothing there. Nada. Even though Starry Night shows the same arrangements of 6141/45/46/47 - I just checked the program - I think *both* programs have this wrong. Before I get on line and check, anybody know for sure? 6138 is in the same boat. I looked where TheSky pointed, but saw nothing. Not even a suspect. So for me, 6138 and 6141 remain a mystery.
NGC6150About an eyepiece field south of 6146 and friends. Very faint and very small. TheSky says mag. 15, but it's more like mag. 14'ish. MCG7-34-33 also spotted to the east of 6150.
NGC6154A star-hop from Tau Herculis north to a 6th magnitude star (it's not too bad; it's the only bright star around) and then NE another degree to 6154. Very faint; low surface brightness.
NGC6158Got here via way of 6166 (previously logged at Lassen, along with some faint companions); same field. Easy to spot, small and round. Didn't spend any time this evening reexamining 6166 and its friends.
NGC 6173 and 6175Got here from 6160, just a field away. 6173 is pretty bright with a nice core. Slight oval appearance. 6175 is much fainter, and appeared to be elongated.
NGC 6177 and 61796177 is small and faint, but its bright core gives it away. I would have missed 6179 altogether, but I had TheSky's magnitude limit set for a ridiculous 17th mag, so it appeared on the screen ... and I thought I'd go after it. 6179 was nothing more than a stellar object with a hint of something non-stellar, call it a halo, when viewed with averted vision.
NGC 6186Three eyepiece fields due east of Beta Herculis. Faint and small, but some easy-to-identify star patterns in the eyepiece field lead you right to it.
NGC 6195Three eyepiece fields due west of Eta Herculis. Like 6186, faint and small.
NGC 6241An eyepiece field SE of 52 Herculis. Faint and small. UGC10586 visible to 6241's east. At higher magnification, MCG8-31-3 "stuff" to the NW can be detected, but I'm not certain what it is I was seeing here. I thought I detected two faint fuzzies, but I'll have to revisit the MCG8-31-3 area from darker skies. (MCG8-31-3 not officially logged).
NGC62552.5-deg. due east of M13. Faint and large; I'd have missed this without TheSky pointing the way and identifying the associated star field. Very low surface brightness.
NGC 62674-deg. SW of Delta Herculis. Faint, large and round. Again, without TheSky pointing the way, I probably would have missed this one.
NGC 6278One eyepiece field due east of 6267. Faint and small, but not difficult to detect. Could not detect 6276, however, reported to be to the NW.
NGC 6283Centered the Telrad between Beta Draconis and Tau Herculis, and them worked to match TheSky’s starfield. Nice double star to the SW leads right to it. Faint and small.
NGC 6301Push the 'scope 2-deg. SW of M92. Very faint, large. Could not detect CGCG225-50 to the SE.
NGC 6371 and 6372Both are less than a degree NW of Lambda Herculis. 6372 relatively easy to spot, faint but with a nice core. 6371 much fainter, just to the NW of 6372.
NGC 6389Sort of forms a triangle with Alpha Herculis and Alpha Ophiuchi. All I had to do was match up the field in the eyepiece with that of TheSky. Finally a relatively bright item; very easy to spot.
NGC 6490/6495/6500/6501Residing in the same eyepiece field, these galaxies are close to the border of Ophiuchus, and sort of form a triangle with Alpha- and 72- Ophiuchi. A number of bright stars around, so it's pretty easy to match TheSky's field to find them. 6500 and 6501 are two bright twin galaxies, same size, nice cores. 6495, to the west, is fainter, but with a nice bright core, too. 6490, a bit further to the NW, is much smaller and fainter than any of the others.
NGC 6555About 3-deg. to the ESE of the 6500/6501 pair. Relatively bright, but uniform.

Whew! That was a boatload of galaxies! I finished up the night with a look at Mars. Although a fair ways from the meridian, and still a bit low, the planet was really looking pretty good. Ought to look great come late August.