Saturday, August 26, 2000

Out From The Shadow A Night At Henry Coe

Henry Coe State Park sits inland from California's coastal range of mountains. It is the state's largest park by size, and due to the status of wilderness area, possibly the state's least visited on a visitor per acre basis. It sits 2400 feet above a long thin valley containing the communities of Morgan Hill, Gilroy and Hollister, as well as lesser populated towns. One can stand in the overflow parking lot half a mile before Coe's park headquarters, and look south a few dozen miles to the twin summits of Fremont Peak State Park, once the heart and soul of amateur astronomy in the San Francisco bay area.

Saturday the 26th of August, 2000, I arrived mid afternoon to join other readers of TAC's mailing list for a night of observing. I found only one other observer in the overflow lot. An hour later, four of us sat under the shade of the large oak at the southern extreme of the lot. Looking south, I could see fog laying in early around the communities of Gilroy, Hollister and San Juan Bautista. Fremont Peak looked like it might have a dark night. A deep haze covered the valley northward, extending to San Jose, where it was grayish and high. We might have a good night at Coe as well. In the last few hours before sunset approached, many old and new observers drove into the lot, filling it up again almost beyond capacity. By true dark, there may have been 35 to 40 telescopes of all types and sizes. This is always a wonderful occurrence, as people share views, get to meet other members of their avocation, build camaraderie, try each other's equipment, and learn the sky with observers of a wide range of experience and preferences. An observer's dream come true!

Before describing some highlight objects I observed, I'll comment on the wonderful conditions. Temperatures never dropped below the 60's Fahrenheit during the night. Relative humidity was an amazing 19 percent at astronomical dark, rising to perhaps 25 percent with no breeze by the time I turned in at 4 a.m. As the night progressed, all the cities in the valley dimmed out under the thickening low fog, even San Jose was dimmed considerably by about 2 a.m. We could see Fremont Peak above the fog to the south, so observers there must have had some light dome to their north from San Jose as there was to our northwest. But, the transparency and steadiness of the night from our location was outstanding. It was not easy to quit observing.

I began observing what remaining objects I could from my list of Herschel objects. Just the night prior, at Fremont Peak, I was observing with my daughter Mimi, both of us using 10" Dobs, and getting her an earnest start on the Herschel 400 list. My observing program is the complete Herschel list (2500+ objects).

Due to the peculiarities of weather, I have nearly completed the summer and fall objects, with many remaining in winter and spring. In Bootes, I logged 4 dim galaxies before the constellation had descended too low, and was washed out for the dimmest objects by the city glow.

In Bootes I logged NGC 5992, 5993, 5500 and 5579.

I flopped around for a while, not knowing what to look at. Visiting friends, having people come up to my 18" Dob and ask to see this or that object, which I enjoyed doing. I made the rounds for a while. Then a friend came up asking to see a planetary nebula in Lacerta. IC 5217 turned out to be a fun object to find. Located in the northwest part of the "diamond" (head?) of the lizard, this planetary is 1' in size, tiny, near stellar. With my 20 Nagler it appeared very slightly non-stellar, and just a bit more so with the 12 Nagler. The location is between naked-eye stars 3-Beta Lacertae (mag 4.4) and 4.6 4-Lacertae. Just over halfway between these stars, to the north of center, are a pair of dimmer stars, bisecting the line between the bright pair, mag 6.5 and 7.4. Identify the mag 7.4 star by the distinct chain of dim stars, perhaps 10 of them, strung together over a 12' area to the SW from the mag 7.4 star. The planetary is 16' S of the mag 7.4 star. Have fun hunting this one.

After a while, looking at page after page of my Herschel list for some unfound objects, I came upon a handful in Hercules. Many of these were rather forgettable, ranging from dim smudge to extremely dim smudge, nothing really remarkable. However, NGC 6146 would be very nice in a real dark sky, since it is in the midst of a very rich galaxy field. Same could be said for NGC 6166, in even a richer galaxy field. Oh for real dark skies! Another rich cluster surrounds NGC 6173, the next find on my list.

In Hercules, I logged NGC 6146, 6154, 6166, 6173, 6186 and 6372 before it began sinking into the brighter skies.

Out of objects again, I fumbled for a bit. Then I remembered the printout I made of the SAC Deep Sky Database. Lots of objects other than Herschel. Out came the Andromeda listing.

I listed three "objects" as spectacular. First was NGC 72. Located conveniently in Andromeda one third of the distance and on the line between Alpharatz (Alpha Andromedea) and the next star in "the chain" of the constellation, mag 3.2 31-Delta Andromedae, this object at 100x appears to be a fairly large smudge, at about 5'x3'. Upon closer examination, it appeared some stars overlay the object. With progressively higher magnification, eventually up to 302x, the "galaxy" broke up into five galaxies, with hints of two more. All within the small smudge. The group included NGCs 67, 68, 69, 70, 71, 72 and MCG5-1-70. Outside of the group NGC 74 could be viewed averted E some 6'. Many people observed this interesting tight group in my telescope.

The other standout of the night was NGC 83, also in Andromeda. This galaxy is among the brightest of eleven galaxies in the 20mm Nagler's field of view. Find this field 2.5 degrees perpendicular to the midpoint of the line described by Alpharatz and Algernib (the north eastern most star in the Great Square of Pegasus), on the outside of the square. NGC 83 will be among a group of three mag 11.2 stars, all within 2' of the galaxy, and forming a small parallelogram with it. A mag 7.5 star sits 23' E, and a pair of stars separated by 2' sits 14' W of the galaxy. About 6' S of NGC 83 is NGC 80, appearing almost the same brightness at mag 12.1 compared to 83's mag 12.5. Both have surface brightness in the low 13's. Careful study brought out NGCs 90 and 93, mags 13.7 and 13.3, 8' and 10' E of NGC 83 respectively. Interestingly, The Sky by Software Bisque has NGC 90 misidentified as NGC 91. Returning to the little parallelogram of stars that includes NGC 83, look 5' N and find IC 1546 and NGC 85, sitting a mere 1.5' apart in an E/W orientation. These two are a great catch, as both are under 1' in size, with magnitudes in the high 14's but higher surface brightness due to their small size. Almost 3' further N of the last pair is the dim galaxy NGC 86, tiny at 0.6' x 0.2' ... at mag 14 and high surface brightness of 11.5. From here, turn W about 12' to find NGC 79 and IC 1542 , two galaxies in the mag 14 range. The last two objects I found in this field were NGC 94 and 96, sitting close together (5' separation) and N of the line between NGC 83 and the mag 7.5 star to the E. NGC 94 is the closer of the pair to the line, but was a "maybe" with averted vision. NGC 96 was about mag 14, but again, its small angular size gave it a significantly increased surface brightness.

Eleven galaxies in a field no larger than the size of a full moon. What a place!

The total logged objects in Andromeda last night included: NGC 911 (the emergency galaxy!), NGC 7618, NGC 72, 67, 68, 69, 70, 71, 72, MCG5-1-70, NGC 74, 846, 43, UCG 130, NGC 89, 71, 80, 83, 90, 91, IC 1546, NGC 85, 86, 94, 96, 74, IC 1542, NGC 233, 562 and NGC 39.

Not a bad night.

Around 3:30, with only a few of the observers remaining, I trained my scope on M33, HII regions galore. M76 was a fun target, showing a bright bi-lobed shape. M74 was still dim, but obviously a good sized spiral galaxy without much detail. M77 showed its bright Seifert core and round face on spiral disk, but little if any arm detail. A quick jump over to NGC 246, one of my favorite planetaries in Cetus, then NGC 7331 which showed a bright core and lengthy elongation of its spiral arms and three small galaxies nearby. Remembering Jay Freeman's direction on how to easily find Stephan's Quintet, I had no problem getting there, but did not have the nice high power view Jay had the prior night in his C14... still, a nice view at lower power. Back to the Blue Snowball, which I had seen hunting a nearby galaxy earlier in the night.... what a great color!

After several more "tourist" objects, I settled down for some great views of M31. Sitting almost at zenith, the twin dust lanes were so outstanding I began calling people over. I felt as if I was seeing some ragged edges to the lanes, and their sweep was greater than what I ever remembered. NGC 206, the bright emission knot containing blue supergiant stars south of the core looked much like a large galaxy, very obvious. M32 was elongated with a bright core. Detail I see usually in much darker skies were putting whipped cream and a cherry on the top of my night! What views.

I finally swept over to M110. This large elongated galaxy just NW of M31's core is really bright. It stuck me how it is overshadowed by its giant neighbor. Placed almost anywhere else in the sky, it would be a showpiece galaxy, much as Henry Coe State Park and other lesser known sites in the bay area have been in the shadow of Fremont Peak for years. But things change. Coe, Pacheco, Montebello and other locations have emerged as excellent alternatives, exceeding "the Peak" in many important ways.

There was even someone out last night inviting some of us to come to his private property, 4,000 feet high up in the Ventana Wilderness, where he has room to set up telescopes around his observatory and 30" scope... a Fremont Peak ex-patriot.

More on that later. I'm still savoring a really excellent night of observing among so many good friends and acquaintances at a great location... Come join us next time!

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