Observing In So. Cal. (long)
This past Monday and Tuesday I had the pleasure of observing from Mt. Pinos in Southern California. For those who have driven I-5 from Northern California down to LA, Mt Pinos is about 20 miles to the West of the Grapevine Grade, in the Ventura county mountains overlooking the San Fernando Valley. The summit is 8800+ feet, with the highest vehicle access being a parking lot at 8300' where the base lodge for nordic skiing is located. Skiing this near LA? Yep, I was surprised too, but in fact there were still large patches of snow on the shaded northern slopes near the summit.
(Some of you may recall my original intent was to travel to Cone Peak, near Big Sur. However a last minute phone call to the Hunter-Ligget military base, which must be traversed to reach Cone Peak, revealed that the road was closed. With the trucks already packed and our hearts leaning southwards in hopes of better views of Mars, we chose Mt Pinos as our backup destination.)
The parking lot at 8300' is good sized, about the size of a football field. people came and went but there were about a dozen or 15 scopes there each night, ranging from an 80mm refractor to a pair of 20" dobs. The number of observers surprised me for midweek, but some regulars who were present told me that on balmy New Moon weekends the scope count can exceed 120. This would be very crowded...I think midweek visits are the ticket for Pinos, at least in Summer. The lot is surrounded by pine trees, which limit the horizons in all directions. While not ideal, this is neither a great tragedy since the southern horizon is somewhat washed out by the considerable skyglow rising from the LA megapolis. The sheltered location provides good protection from wind, which we heard whistling through the upper branches of the trees but which I never found troublesome down in the parking lot. I didn't see a drop of dew either night.
My friends Ken Sablinsky and Rich Campbell drove down Sunday night and reported fabulous transparency, with good seeing. I joined them Monday, and with me brought high cloud cover, which didn't clear out until midnight or so. When it did, I was able to count stars down to magnitude 6.7 near the zenith. Seeing was only ok...I had better views of Mars from the SVAS observatory site last week. Ken told me that both seeing and transparency had been a little better Sunday night, and regulars agreed that it was not especially dark for Mt. Pinos. Tuesday night was completely clear, and again I reached magnitude 6.7 naked eye.
It was dark enough that I thought to undertake (during "rest periods" in the lounge chair) to see how many globular clusters I could pick out naked eye. M13 was easy, and despite the southern skyglow I was able to pick out M22. These I had seen before, but for the first time I was also able to detect M5, M4, and M92 naked eye! All three required averted vision but were held steadily, with M4 being the easiest. M5 is brighter but close to a fairly bright star; alternating between direct and averted vision made the cluster "blink" in and out of view. I had intended to get out my charts and try for dimmer globulars in Ophiucus, but seeing M92 naked eye got me so enthusiastic about the conditions that I had to get my eye back to the eyepiece, pronto!
Seeing was a little worse Tuesday, so that at 165x and 215x I had to wait for steady moments to pick out fine details in DSOs. Despite this, with patience I was able to make some very satisfying observations. Below are those that I found most interesting, culled from both nights of observing:
M13: For only the second time I was able to see the "Propeller" of dark lanes in the cluster. Now that I know what to look for, I think it is not a very difficult feature. The propeller is well offset from the core of M13, with its hub on the South-following fringes of the cluster. The lane radiating outwards, away from the core, is easiest to see; once this is located the two other lanes which run more or less tangent to the core are not too difficult in the 12.5" at 165x
NGC4361, PN in Corvus: One experienced observer calls this the "Lawn Sprinkler," and I finally saw why: With the Ultrablock filter at 215x a spiral shape was very apparent, in fact the nebula looked more like a spiral galaxy! Without the filter the spiral shape was harder to see, but the central star was prominent.
Hickson 68, compact galaxy cluster located 8* south of M51: Three small, bright galaxies and two that are fainter but still easy in the 12.5" This is one of the most accessible Hicksons, and should make interesting viewing even in an 8". I wonder how big of a scope is required to see the spiral structure in two of the brighter galaxies?
Abell 1656, Galaxy Cluster in Coma Berenices: Two large eliptical galaxies at the core of this clusters were held easily with direct vision; averted vision brought out at least half a dozen smaller members in the same 1/2* field at 165x. Sweeping the surrounding fields revealed several more individual galaxies, and an unevenness to the sky background that suggested unresolved multitudes. I could have spent hours logging each one, but without regular access to such dark sites I decided to soak in the overall impression for a while and move on to other quarry.
Hickson 79, Seyfert's Sextet: A very compact galaxy cluster, appearing small and faint even at 350x in the 12.5". Two galaxies could be seen steadily with direct vision, with the third at the vertex of the cluster's "V" seen clearly during steady moments. The edge on galaxy that forms a "wing" to the preceding side of the clsuter was seen about 25% of the time with averted vision, and its elongated shape and orientation clear. The more diffuse galaxy on the following "wing" was only suspected, and the small round galaxy near the center was not detected, likely due to the only fair seeing rather than dimness.
North American and Pelican Nebulae: My logbook entry begins with "Fabulous!" Eye-candy after the difficult Sextet; this may have been my best view ever of these objects. The North American was bright and easy, revealing lumpy structure even without a filter at 47x in the 12.5". Ultrablock and O-III filters brought out even more detail, and made the Pelican an easy target, too: the dark lagoon bisecting it and much filamentary structure were in evidence.
NGC6888, the Crescent Nebula in Cygnus: Eye-popping at 165x with O-III filter. The dimmer side of the nebula was so prominent that the usual "E" shape disappeared into an egg-shaped glow, rife with rippling strings and knots. The brightest regions, which compose the "E" that I've observed from less-dark sites, seemed to link the brightest involved stars like a network.
Veil Nebula: Another great view of a familiar object. Especially remarkable this time was the amount of detail inside the "ring" of the nebula. Pickering's Triangular Wisp was especially prominent and revealed much detail under the O-III.
IC5146, the Coccoon Nebula in Cygnus: at 70x, large and somewhat faint, but immediately recognized and held directly. Several stars involved in a roundish glow with uneven edges and internal mottling. The nebula overall is somewhat condensed and appeared to be crossed by three parallel dark lanes running from North-preceding to South-following.
Hickson 56: A _very_ compact galaxy cluster beneath the bowl of the Big Dipper, and near the face-on spiral NGC3718. At 215x, an elongated glow was seen directly, resolving into two galaxies with averted vision, the following galaxy being the brighter. In moments of steady seeing, the third galaxy of the chain seemed to resolve briefly out of the glow. Another faint galaxy was detected offset from the chain away from NGC3718, so I "bagged" 3 or 4 out of the 5 galaxies in this group.
Barnard's Galaxy, NGC6822: At 47x, a fairly large, quite elongated glow, which seemed on the verge of resolution into stars. It more closely resembled a Milky Way star cloud than an external galaxy. The cute little green planetary NGC6818 could be seen nearby, clearly nonstellar at low power.
NGC 4244, one of many fine galaxies in Canes Ventatici: A bright, very large, extremely elongated edge-on with pointed ends. Unlike the more famous NGC4565, this galaxy displays no clear dust lane or central bulge. It appears unevenly illuminated and subtly mottled in the 12.5" at 165x
NGC4395, Galaxy in Canes Venatici: Large and diffuse, surprisingly difficult given the listed magnitude of 10.2. Passed over several times at 165x, 70x provided a wide enough field to distinguish the galaxy from the background. Somewhat elongated, only slightly concentrated and unevenly lit. Photos suggest it might reveal interesting detail in larger scopes.
NGC4449, Galaxy In Canes Venatici: A new favorite, very interesting, bright, somewhat large irregular galaxy. The brightest region is somewhat rectangular, with fainter irregular wisps reaching outwards. At 215x I noted several bright spots in the inner region, at least two of which appear to be foreground stars but the others possibly bright knots in the galaxy itself. Not far from Beta CVn and the Coccoon Galaxy.
I also viewed many other interesting galaxies in the constellation of the Hunting Dogs, but I've reported on many of those before and this post is running overlong. On the whole it was a fine couple of nights, and days: there are several good hiking trails radiating from the observing site at Mt Pinos. On Tuesday I took advantage of the one to the summit, where I was rewarded with fantastic views of the Central Valley and even Mt Whitney rising out of the haze! It's also supposed to be a good location for spotting California Condors, though I didn't see any.
If anyone has more questions about the site or the objects mentioned, I'd be happy to answer them via the list or privately as appropriate.
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