Tuesday, April 5, 2005

Wildflowers from Coe

Springtime has arrived at Henry Coe State Park. Wildflowers are beginning to appear - notably the California Poppy, sprouting up along the roadsides and paths, like clusters of galaxies in the spring sky...

It was an excellent night at Coe. Four observers were present bringing 20", 18", 15" and 10" Dob, and a nice pair of Vixen long focal ratio mounted binoculars. I arrived at 7:30 pm, in time to watch the sun set over the coastal peaks and get my equipment set up. The sky was very clear and the steadiness of Saturn gave us hope for good clean star images, which is how things turned out for most of the evening. The parking lot was dry and without dust, and there was no breeze at all until around midnight, and even then it was only slight. Transparency was excellent. In the 20" I viewed detail in the Ghost Of Jupiter (NGC 3242) that I've never seen before, and M51 that rivals the best views I've ever had. Too bad the next morning was a work day, or I'd just now be getting to sleep instead of writing this report.

The view of the night was the Ghost of Jupiter. M51 was amazing, but I've had views similar to last night's in the 30" at Fremont Peak, and at times at high elevation from Mount Lassen. The Ghost of Jupiter usually appears to me as a very bright large planetary disc with little detail. Just a bright ball. In the 20" at 280X there was tons of detail. A small central dark disc with the central star - a pinpoint - popping in and out. A bright ring around the dark disc, then a grey diffuse oval around the bright ring... and... further out, a large faint envelope of nebulosity. This was without a filter.

My personal observing program was to continue on the Herschel 2500 list. I went observing last night because springtime is the big "hole" in my list - the weather is usually so sucky, all I have left are springtime constellations - Coma Berenices, Virgo, some of Hydra and Corvus. Coma was already up decently in the east at astronomical dark. I also should note that this was my first night out since the trip to Chile. I think I prefer Orion and Leo upside down! ;-) And, while mentioning Chile, there was talk about a return trip next year with a 20" and 18" Dob. Is it unsightly to salivate while dreaming?

Coma Berenices has some very good stars to hop from. My 18" Obsession is equipped with a 10x70 Celestron finder and a Rigel Quickfinder. We were talking about setting circles, but so far I've resisted adding Sky Commander to my setup. The eyepieces I used were all Naglers, the 20, 12 and 7.

I am at the dim end of the list in Coma - I began with NGC 4923 - a magnitude 14.67 round galaxy with a close companion - NGCs 4921, 4919 and 4911 (there are many other galaxies in this rich area). The four galaxies were all very faint in the 20 and 12 Naglers. I compared the surface brightness (SB) of 4923 and 4921 - and the dimmer magnitude 4923 had about the same SB. This galaxy field is easy to find, just west of the naked eye pair of mag 4.5 stars 41 and 43 Comae Berenices, located between Arcturus and Berenices Hair.

NGC 5004A was next, and nearby. The scope only had to be moved slightly, to the west of 43 Comae Berenices. This galaxy is very faint and located very close to a mag 12 star. The galaxy is non-descript, except for an elongation NW to SE. NGC 5004 is in the same field of view (FOV). It is bright, has a noticeable central concentration with a stellar core that is at the edge of visibility. I enjoyed locating these galaxies as there were some nice finder stars to their NE that are at the edge of the FOV about 23 arcminutes away. NGC 5004 is mag 13.89 type SO, 5004A (designated 5004C in NED) is a mag 14.6 type SB.

Just under 2 arcminutes to the NW sits the nice pair of galaxies NGC 5056 and NGC 5057. My target was 5056. These are a pretty view, sitting just outside the short leg of an obvious right triangle of bright stars. Both objects seem extended N/S, and 5056 is significantly larger than 5057, and more extended. 5057 has a bright central region . 5056 is a mag 13.7 type Sc, 5057 is mag 14.04 and SO.

I was surprised that my next target went unnoticed, in the same FOV as 5056 and 5057. NGC 5065 is NE of the other pair, just outside one of the corner stars of the right triangle. Once I knew where to look, it was an obvious galaxy. Combined with the stars of the triangle and other galaxies, I found they created a nice visual arc. 5065 seemed to be oriented E/W and was the largest of the three galaxies in the FOV. It was hard to tell if it was round, as it seemed to have some internal darkening that caused me to guess it might be disrupted or a face-on spiral. There was a very faint star "in" the galaxy embedded its northern section. NGC 5065 is mag 14.20 and type Sd.

While observing, some lost campers drove by, sat with their car lights on at the entry gate, so we hid behind our trucks, waiting for them to make their move. Eventually they drove off, up to the campground. They would return later and get a sky tour in the 15" Dob. Two of the observers commented how little traffic there was at Coe... this was their first time observing from the site. Well, it was a Tuesday night, but yes, it is less trafficked than Fremont Peak (which is what it was being compared to). There were also comments that Coe is as dark as the Peak. Certainly the city lights to the NW are there, but positioning your vehicle properly and looking to the south and east, it can be pretty dark, especially when fog blankets the cities. I did a limiting magnitude count in the Bootes - Coma triangle - at 2 am. - I can safely say it was mag 6.6, and maybe mag 6.9. What was cool was the transparency!

Just a degree south of NGC 5065 is the bright roundish galaxy NGC 5089. In the same FOV is UGC 8377, obvious off a string of stars to its SW. 5089 is a type Sb at mag 14.02, UGC 8377 is a round type E at mag 14.62.

I next moved 14.5 degrees south, using Arcturus and Murphid (mag 2.6 Eta Bootis) to point me to NGC 5180 and NGC 5172. These galaxies are both bright (mags 13.96 SO and 12.63 SAB) and have a mag 7 star nearby. 5180 is kind of trippy, I had to call a couple of other observers over to peek at it... it looked like a dim globular rather than a galaxy, but it turned out there were three very dim stars in front of the galaxy, giving it the appearance of having stars visible in the object. The stars would blink in and out, so we began calling it the Blinking Galaxy. 5172 appeared to be a larger disrupted galaxy or face-on spiral. 5180 was a small amorphous haze amid the dim stats...

One of the happy accidents that occur star hopping, rather than using a goto or DSCs is running into unexpected objects. When hunting for NGC 4529 (this one took for-ever!) I found that 24 Comae Berenices is a beautiful double star - sapphire blue and a creamy ivory gold, nearly equal magnitude. Worth the trip!

I finally did find NGC 4529. Hopping in the Coma Cluster is tricky! There is a dim "V" of running E/W and N/S with its apex to the SE of the galaxy. The galaxy was extremely difficult, I could pick it up only about 20 percent of the time. It was nothing more than a very dim haze with several very faint stars nearby. This galaxy defines the term "lumpy darkness"... It is a small slash at mag 15.0, type Sc.

The next object was just over eight degrees to the NNE, back near where I started at 41 and 43 Comae Berenices. I was after NGC 4789A, aka UGC 8024 - a mag 13.94 type IB galaxy with a very low SB. NGC 4789 was quite easy to pick up to its SE. But the dimmer "A" galaxy was visible only as a large haze about 33 percent of the time, nicely tucked in between four dim stars. I had estimated its size as twice that of 4789 and elongated NE/SW. This one is a toughie!

45 arcminutes to the NE I found NGC 4816 - easy, bright, elongated 3x2 NNE/SSW. Visible in the same FOV was MCG5-31-13. 4816 is a mag 13.8 type SO, the MCG is mag 15.6! type E. Woohoo! A dim one!

By this time it was getting late and cold. I had spent way too much time hunting for 4529, a good lesson to kick such problems to the curb, move on, and try again another night. The breeze was just beginning to kick up and I thought of heading home. But, it was such a good night, I pressed on for a few more targets....

NGC 4840 was easy, and actually in the same FOV as 4816 (but at the very edge of the field). It was very near the brighter galaxy NGC 4839. I also saw NGC 4842A, but not the B component, both located just off 4839. I did pick up MCG5-31-37 in the same FOV. 4816 is a mag 14.7 type SAB, 4839 mag 13 type cD, 4842A mag 14.9 (no type designated) and the MCG mag 14.9 type SB.

A half degree to the NE was a real treat - I was going for NGC 4869 and discovered it is in a rich galaxy cluster. In my FOV I counted seven galaxies easily. I'm sure there would be more, but the breeze had begun to deteriorate the seeing, and stars were starting to look like small round galaxies or planetaries. Using The Sky I can see that with a mag 15 limit, there would be probably 30 galaxies in the 47 arcminute field of my 20 Nagler. This cluster will be on my list again in the future.

I was about to tear down and decided on one more object (this sure sounds kid-in-the-candy-store-ish!) It was a tough one. NGC 4911A was fortunately in the same FOV as the prior galaxy, so it was easy to get to. Seeing it was the hard part. This one is a mag 15.30 type SO and only 0.53 x 0.26 arcseconds (which helps increase its surface brightness). It appeared to be a small spike perpendicular to NGC 4911 to its S. There is a nice image of this small "spike" among many of the galaxies in the rich cluster I mentioned, at:


That was it for the night. It was 2 am when I pulled out of the lot. It was an easy drive home, and I was very satisfied after a great night of observing. I plan to take advantage of other mid-week opportunities during the spring. Wildflower season goes by too quickly.

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