2003/03/01 At the River's Head, and the Bear's Paws (Lake Sonoma/17")

by Robert Leyland


After a long day of youth soccer tryouts I was pretty tired, but the weather was great, just a few puffy clouds, so I set off for Lake Sonoma, CA somewhat hopeful. On the way up, it's a bit over an hours drive, the SF bay Area microclimates changed a couple of times, with some clear areas, and some very high thin cloud. Luckily it seemed to be relatively clear at LS.

There were several others set up when I arrived at about 6pm, and a few more arrived after I did, a nice sized group for a new moon night.

David Silva had an accurate GPS unit with him, and took a few readings, giving us a better value for the altitude at Lone Rock flat.

ObserverRobert Leyland
Date1 Mar 2003
Time1930-0100 PST (UT -8, or 0330-0900 2 Mar 2003 UT)
LocationLake Sonoma CA, 3843'N 12302'W Elev ~1100 (Lone Rock Flat)
Weather10 - 7C Temp, 70 - 87% Humidity, sunset breeze, and a few light puffs later
SeeingLM 6.5+, transparency 8-9+/10, steadiness 9/10
Moonnew moon
Equipment17.5" F5 Dob, 9x50 RACI Finder
EyepiecesPentax SMC XL: 21mm ~ 100x (default), 14mm ~ 160x, 10.5mm ~ 210x

Early evening transparency was affected by some light high altitude cirrus, that dispersed by 9pm. After that it was very clear, and some deep objects were seen. We also had strong zodiacal light visible until after 8pm. At one point during a rest break I counted 8 stars in the Pleiades, and we noticed that the Hyades looked like a big "N" where the "V" of Taurus usually sits.

I started in Eridanus, last week I was looking for a specific galaxy group, and took my time going from one object to the next, so that by the time I reached the cluster, it had moved behind a tree. I'm not one to support using a chainsaw to aid our hobby, so I made sure to go for it early tonight.

Unless otherwise mentioned all objects are galaxies.

ERIDANUS

NGC 1723, 1721/25/28: A very nice little galaxy cluster. 1723 is by itself, and the other three from a closely spaced arc about 20' away to the S. Each of the galaxies are small circular blobs with star like cores. 1725, the center galaxy in the arc, is fainter and the core is less well defined despite it being one of the brighter QSO like objects.

I revisited NGC 1667 but it was not as well defined as last weeks view, where I thought I could make out some structure.

Nearby NGC 1659 is another small circular galaxy, with a pin point core. A small faint field stars is offset to the SW.

NGC 1637 is a nice face on circular galaxy, between Mu and Nu ERI. It has a bright, but broad nucleus, and darker regions in the halo hint at spiral structure. A faint pinpoint field star shows in the NW of halo.

NGC 1638, yet another small circular galaxy with a stellar core, notably fainter than 1637.

NGC 1625, 1622, 1618 a very nice triple immediately adjacent to Nu ERI. The big star is bright enough to be distracting, but the galaxies are all visible with the star in view. At 160x it was easy to move the star out of view, and the galaxies really shine. At 160x each is a distinct shape, elongated almost edge on (1625) with a faint star at the northern most tip, oval with a diffuse core (1622), and more circular with our friend the stellar core (1618).

NGC 1600 on the other side of Nu ERI, and a bit further out, is a larger circular galaxy with a diffuse, but bright core that looks somewhat irregular, another fuzzy patch is nearby to the NE. From U2K I gather this is NGC 1601 a galaxy with surface brightness of 13.8.

By this time Eridanus was sinking into the west, and I had another challenge object provided by Steve Gottlieb. I've recent picked up an interest in quasars (QSO) and he had a chart for the well regarded double quasar in Ursa Major.

I checked on the NED database, and found over 200 scientific papers referencing this object, simply known by its galactic coordinates 0957+561. The Twin Quasar has two components (A and B) both 16th magnitude, and with redshifts around 1.414, most likely visible due to gravitational lensing.

The QSO can be found at 10h01.3 +5554' south of galaxy NGC 3079, it is marked on chart 25 of U2K, but getting an accurate finder chart is a must. The galaxy (see below) points at the QSO which is adjacent to a faint group of stars, the nearest being a mag 14.2 speck. The QSO was visible only briefly in averted vision, when held it was noticeably non-stellar but it was too difficult to tell the actual shape.

Steve Gottlieb, Matt Marcus and David Silva were all able to view the faint little thing, confirming that I wasn't just imagining it.

Now about the galaxy NGC 3079, it's a beauty, even if you don't plan on quasar hunting, this object, and it's two companions are well worth the effort to find. It is a large edge, thick (5:1), edge on galaxy with a dusty lane along the center (best viewed at 160x). Nearby is NGC 3073 a smaller dimmer 2:3 oval galaxy. Also there is a faint smudge, closer to 3079, that is hard to detect, but can be held with averted vision which is MCG+9-17-9.

Steve also supplied a diversion in the form of IC 2003 a planetary nebula in Perseus. Small but bright, and clearly non-stellar. At 380x in Steve's scope it looked a little asymmetrical, being brighter on the SW side. He was picking up small planetaries and faint IC galaxies all evening.

By way of a challenge he suggested finding NGC 1569, a starburst galaxy in Camelopardelis. While not that difficult to find (it's midway between Alpha CAM and Kemble's Cascade), it is a very interesting galaxy as it is notably asymmetric. At low power it is an edge on smear adjacent to a moderately bright field star. At high power (425x - Pentax 5.2mm) you can see a stellar point offset from center, and with averted vision a second point closer to the blunt end of the galaxy. 1569 is also a well studied object, as here are 10 known radio sources inside it, and hundreds of references in the astronomy literature.

Back in UMa, I returned to galaxy hunting, picking up NGC 2841 a very nice, large elliptical with a nicely defined core and structure visible in the halo (220x). 3 stars are visible at one end of the galaxy, with one quite faint star at the tip of the halo.

NGC 2681 is a faint elliptical (2:3) with a bright stellar core. At 100x it looks like a "dirty" star, but the shape of the halo shows up at 160x.

NGC 2693 has a small circular halo with a slight brightening offcenter, and a stellar nucleus.

NGC 2701 is a modest round glow, at 160x a faint core can be seen but it is ahrd to detect due to the presence of a 10th mag star at the edge of the halo.

NGC 2639 is a nice elliptical galaxy elongated 4:1 with a 2:1 elliptical core.

NGC 2654 a slashing edge on galaxy (7:1 ratio) with a dash for a core. Starhop from 1-O UMa.

NGC 2742 has a diffuse oval shape but no core is visible at 100x. Moving to 160x the shape sharpens to a diamond, with a slight brightening at the center - not really a well defined nucleus.

NGC2768 is a nice bright 3:1 ellipse with a well defined nucleus and stellar core. Overall this is a pleasing object to view as the galaxy is set in a nice cluster of stars (160x).

NGC 2880 another small circular galaxy, with a bright core. Averted vision shows a stellar point inside the core.

NGC 2950 has yet another small circular halo, but it has a nicely defined core. Close to Nu UMa, and between it and a small triangle of stars in the finder.

NGC 3043 a faint, small edge on galaxy. At low power it looks like a hyphen, at higher power there is no sign of a core.

NGC 2685, the "Helix Galaxy" shows as a small 7:2 oval halo with a sharp elongated core. A pretty view, but it's unclear to me why this is called the helix.

This brings us to a couple of Ursa Major's better known galaxies: M81 and M82.

These are easily visible in the finder scope, looking a bit like a baseball bat, and a beachball. Using low power (55x in a 40mm Pentax) the two huge galaxies just fit in the field of view. M81 is a lovely oval with a strong central core, and M81 is edge on with disturbed dusty clouds along its length.

M81 fills the FOV at 100x showing dark lanes in the halo, seen on both sides of the core, but more noticeable at the S end.

M82 at higher power (320x Pentax 7mm) is awesome. It completely fills he FOV, showing close grained knots of bright and dark along the dust lane.

After a series of faint galaxies the big Ms really are a treat.

NGC 3077 is adjacent to M81, a nice 3:2 oval galaxy with a well defined elliptical core.

IC 2754 is a modest sized, very faint oval galaxy near M18. It is hard to see at 100x, but at 160x faint pinprick points are visible in the halo, although no specific core can be seen. A difficult object.

NGC 2976 is a nice 3:1 oval smudge, no core is visible but a field star perpendicular to the galaxy makes a nice contrast. The halo of this galaxy appears to be about the same size as the core of M81!

NGC 2985 a circular galaxy with a soft halo and bright core that showed as a distinct disc.

NGC 3065/66 a small close pair of galaxies, the larger (3066) is a 2:3 oval with a faint distended core (this needed averted vision at 160x to see), while the smaller galaxy (3065) is circular with an easy stellar core.

NGC 3348 is one more small circular galaxy with a bright core. This one also has a field star embedded in the halo.

NGC 3516 is a faint 4:3 E-W oval. No core can be seen at 160x, and set in a non-descript cluster of 13/14th mag stars.

NGC 3184 near Mu UMa in the Bear's Paw, shows as a large diffuse oval glow, with a faint oval core. A 12th mag star embedded in the halo and a fuzzy spot adjacent to the galaxy on the opposite side complete the picture. Checking the picture in NSOG (Fig 62-16 p 395), I didn't notice the structure, but I was likely seeing the bright knot in one of the arms. It was tough to view as this region was very high, close to "Dobson's Hole".

NGC 3319, my initial impression is a large faint oval, but averted vision shows a 4:1 elongated core region possibly surrounded by a faint halo extended at the ends of the core. Pretty cool looking for a faint fuzzy.

NGC 3198 is a large moderately bright 4:1 oval with a very faintly brighter extended core. Some irregular shape can be seen in the halo right net to the core. This is a fairly easy star hop from Lambda UMa.

Wow, it's been a great night, many objects seen and logged. Some faint and fuzzy, others big and bright. Good company, clear skies, can't ask for more.

Ok, well, it could be a bit warmer, as the dropping temperature (7C) called an end to my viewing tonight.