Observing at the Sept. meeting

[petep]

ASSNE 10 Sep 05 post-meeting observing log

Well, we’ve finally got a good night for observing after the meeting, and the back field is filled with scopes. We’re all out on the field by 20:00 hrs. I’ve got my 12” set up and tonight’s plan consists of doing a comparison viewing of some of the stuff I viewed from Arunah Hill plus viewing some asteroids that I haven’t seen yet.

20:15 hrs – 20:55 hrs. Brian and I have our 12-inchers set up side by side and Bernie Oakley has joined me. All 3 of us are trying for Pluto. Without success. Its low, and I can’t even see a 13.4 mag star nearby our target without increasing magnification to 179X.

20:55 hrs. Dan S suggests that I take a shot at Neptune’s moon Triton. I’ve got Neptune just fine at 179X but no sign of anything nearby. Triton shines at a 13.5 magnitude, and later a check on Guide 8 reveals it is only 16-arc-seconds to the W of Neptune. Perhaps it was not knowing exactly where to look, but Dan and I failed to observe Triton. I’ve never observed this moon and will put it on my list of objectives now that I know how accessible it is.

10 Sep 05; 21:16 hrs. 159 Aemilia is a 13.5 magnitude asteroid 131 km in size. It’s bracketed by two pairs of 8th mag stars, and sits just to the W of a 13.2 mag star. I’ve got it in the 12” at 97X. Aemilia orbits Sol at 3.4 AU and is now 2.6 AU from Earth.

Bill Lambert comes by. His 8” SCT has dewed up already. Brian and I are both equipped with dew shields and dew heaters so we’re still going strong.

Dan S comes by again and gives me a hand drawn map showing a dark lot he’s used at Frosty Drew. The guys from Frosty told me about this but I was too tired to explore when I was down there.

10 Sep 05; 21:25 hrs. 739 Mandeville is a 13.3 magnitude asteroid 110 km in size. It is bracketed by an 8th mag star to the E and a 10th mag star to the W, with a string of 11th mag stars connecting the two and running thru the position of the asteroid. I’ve got it at 179X with the 12”. Mandeville has a heliocentric radius of 3.0 AU and is currently positioned 2.2 AU from Earth.

10 Sep 05; 21:45 hrs. 877 Walkure is a dim 14.0 magnitude asteroid 39 km in size. It is in the same fov as 339 Mandeville – approximately 30-arc-minutes to the NE. Lining up an 8th mag star and a 13.2 mag star, Walkure is in line with the dimmer star and 3 or 4 ‘ further out. After 20 minutes of eyestrain, Walkure momentarily pops into view 2 or 3 times in the 12” at 254X. Walkure orbits the sun at 2.3 AU and is now 1.4 AU from Earth.

10 Sep 05; 21:58 hrs. 582 Olympia is a 13.8 magnitude minor planet 47 km in size. There are three 9th mag stars nearby, and I’ve got it in the 12” after increasing magnification to 179X, and with the use of averted vision and scope movement. Olympia is 3.0 AU from the sun and is presently 2.1 AU from Earth.

10 Sep 05; 22:04 hrs. 143 Adria is a 13.4 mag asteroid 93 km in size. Bill Gucfa has joined me. Together we observe a bright chain of 9th mag stars identifying the star field and situated to the W of Adria. Adria is bracketed to the E by two close 10th mag stars, and we star hop back using them to identify Adria at 97X in the 12”. Adria orbits Sol at 2.8 AU and is now 1.9 AU from Earth.

Although the sky is wonderfully clear the observing field is starting to clear out. I suspect that many folks forgot to dress for the 40-degree temperatures.

10 Sep 05; 22:14 hrs. 317 Roxane is a 13.2 mag asteroid 23 km in size and 1.3 AU distant. The stars in the goto fov are a bit confusing, so I slew a hair to the E and pick up a 7th mag star for orientation. Bill Gucfa and I then star-hop down and W and then up again across a bridge of 10th mag stars until we have identified Roxane in the 12” at 97X. Roxane’s heliocentric radius is 2.1 AU.

10 Sep 05; 22:19 hrs. 204 Kallisto is a bright 12.5 mag asteroid 51 km in size. I’ve oriented myself in the goto’s fov using a grouping of stars in the NW and a 5.8 mag star 15’ SW of Kallisto. Bill Gucfa and I then star hop up and across the short intervening distance, quickly identifying Kallisto thru the 12” at 97X. Kallisto orbits Sol at 2.4 AU and is presently 1.5 AU from Earth.

10 Sep 05; 22:26 hrs. 389 Industria is a bright 12.0 magnitude, and it is presently only 4” W of a 9th mag star in a N-S chain of 9th mag stars. Bill Gucfa and I have it quickly in the 12” at 97X.

10 Sep 05; 22:43 hrs. 1056 Azalea is a 13.8 mag asteroid 30 km in size. At 20:00 hrs it was sitting on top of a 12.8 mag star, but it has now moved 1” W. Bill Gucfa and I have the star field figured out almost immediately, but Azalea proves to be the toughest asteroid of the night. We work our way up in magnification to 339X before Bill spots it. I sit on the eyepiece for a while and eventually it momentarily pops into view a couple of times thru the 12” at 339X for me as well. Azalea orbits the sun at 1.8 AU and is currently .9 AU from Earth.

10 Sep 05; 22:50 hrs. 345 Tercidina is a bright 11.9 magnitude minor planet 100 km in size. Bill G and I locate it easily thru the 12” at 97X by star hopping thru the star field from a pair of 10th mag stars in the SSW. Tercidina has a heliocentric radius of 2.3 AU and its presently 1.4 AU from Earth.

10 Sep 05; 22:54 hrs. 714 Ulula is a 12.8 mag asteroid 41 km in size. The star field shown once the goto stops is a busy one and I’m lost until I pan the scope a bit to the E and pick up an 8th mag star with a nearby 12th mag companion. Bill Gucfa and I then star hop a series of 11th and 12th mag stars W and then NW and then S until we finally arrive at Ulula. Viewed thru the 12” at 179X. Ulula orbits Sol at 2.6 AU and is currently 1.7 AU from Earth.

22:59 hrs. By now we’re alone of the field. Bill compares the 12-incher’s view of M57 against what he remembers of his 10” scopes view, using 97X and 179X. And he comes away satisfied.

We count the stars in the Great Square as I pack things away (only 4 for each of us). And then we call it call it a night.

Conclusions & Lessons Learned:

Rehoboth isn’t as dark as I once thought it was.

It was unusual to view every asteroid on the list. But tonight Bill caught one that I’d given up on and that gave me the impetus to stick with it.

I’m very surprised that club members packed as early as they did – cool weather or not.

Pete 11 Sep 05

[RobCos]

Rehoboth isn’t as dark as I once thought it was.

I’m very surprised that club members packed as early as they did – cool weather or not.

Pete 11 Sep 05

Pete, one thing i've come to realize is that i'm spoiled by my darker sky at home-as well as Marks for that matter(though I have less sky to work with due to trees). So that would be one reason I packed it in.

Secondly, i'm a cold weather-hardened observer myself, but i'm not much of a cold, WET weather observer. My stuff was drenched and I hate that...I don't mind moist-but when everything is dripping-i'm done. I am heading out tonight for sure in the yard.

[faintfuzzies]

I would have stayed longer but without a working mount I dont have the drive as i do with a working mount..Do not buy a eq6 mount or you might regret it like i do...

[Galaxy77]

Hello Pete.....all

Below is the chart to ascertain your limiting magnitude, using the count in the square of Pegasus. As you can see, things have really deteriorated at the museum since we could count between 8-12 stars just a few years ago.

30 Mag 6.5
17 Mag 6.25
13 Mag 6
9 Mag 5.75
7 Mag 5.5
5 Mag 5.25
4 Mag 5
3 Mag 4.75
1 Mag 4.5
0 Mag 4 (or worse)

Keep the faith

Roger