A night at the beach - Tuesday, Sep 27, 2005

[petep]

Pete's Observing Log of 27 Sep 05 – Little Compton

It appeared that we were in for a perfect observing night, and since I’d missed observing with the club at Mark’s last weekend I made it a point to leave for the dark site in Little Compton by 6 pm. I arrived at 6:50 to find Ken Dore already there. We set up my 12” SCT and Ken’s new 4” Orion short tube APO along the cliff overlooking the ocean.

I’m setup and aligned very quickly thanks to the computer’s choice of very bright alignment stars. I then slew to M13 and it’s reasonably placed considering that I didn’t use the reticuled eyepiece and perform a precision alignment. I then slewed to Venus, but it’s already deep in the soup. While awaiting a workable darkness I sort through tonight’s asteroid chart printouts, putting them in order of increasing RA.

27 Sep 05; 19:42 hrs. 54 Alexandra is a 12.0 magnitude minor planet 171 km in size. It’s already low in the SW at 18h 25m RA, but I’m trying to fill in some of my missing low numbers so I went for it. The sky has been gradually darkening, and at first the only stars visible are five 9th mag stars to the S of where Alexandra should be located. Eventually I’m seeing as deep as 12.8 mag and I’ve got Alexandra in the 12” at 179X. Alexandra has a heliocentric radius of 2.2 AU and it is presently 1.9 AU from Earth.

27 Sep 05; 19:54 hrs. 184 Dejopeja is a 13.7 mag asteroid 68 km in size. It sits to the S of two 8th mag stars. With the 12” at 179X I’m seeing stars to 13.7 mag, and eventually I spot Dejopeja as well. Dejopeja orbits 3.4 AU from Sol and is now 2.6 AU from Earth.

27 Sep 05; 20:00 hrs. 758 Mancunia is a 13.0 mag asteroid 86 km in size. Star-hopping in from three 9th mag stars to the east, Ken Dore and I have got the asteroid as well as two nearby 13.9 mag stars in the 12” at 98X. Mancunia orbits the sun at 3.1 AU and is currently 2.2 AU from Earth.

27 Sep 05; 20:04 hrs. 347 Pariana is a 13.8 mag minor planet currently 2.2 AU from Earth. There’s a 7th mag star only 7 minutes to the SE. I’m seeing surrounding stars down to 13.8 mag, and I’ve got the asteroid in the 12” at 98X. Pariana is 54 km in size and it orbits Sol at 3.0 AU.

27 Sep 05; 20:12 hrs. 126 Velleda shines at 12.2 mag and is 46 km in size. I’ve got it in the 12” at 98X by star hopping in from a 7th mag star 45’ to the W. Velleda has a 2.2 AU heliocentric radius and it is now situated 1.2 AU from Earth.

27 Sep 05; 20:16 hrs. 158 Koronis is a 13.5 mag asteroid 40 km in size. I’ve got it in the 12” at 98X by star hopping from a trio of 11th mag stars 40’ to the S. As the sky darkens I’m seeing to 13.8 mag easily now. Koronis orbits the sun at 2.8 AU and is currently 1.9 AU from Earth.

27 Sep 05; 20:25 hrs. 122 Gerda shines at 12.9 mag and is 86 km in size. The fov is easily verified from a chain of 8th and 9th stars to the S of Gerda, but the asteroid itself is packed in a tight cluster of stars. With the 12” at 98X I’m seeing to 14th mag in this section of the sky. Gerda lies only about 30” to the SE of a 12.7 mag star but I’m able to confirm this sighting because I’d anticipated a problem and plotted out a large scale chart. Gerda orbits the sun at 3.3 AU and is presently 2.4 AU from Earth.

27 Sep 05; 20:31 hrs. 227 Philosophia is 13.7 magnitude. It’s relatively high in the sky, and I’ve star hopped in from a distinctive group of 10th mag stars in the NE. Philosophia lies just 40” S of an 11.5 mag star and I’m seeing it in-and-out thru the 12” at 98X. So just to confirm more positively I also view it (easily) at 179X. This 90 km sized minor planet orbits Sol at 3.4 AU. It’s currently 2.4 AU from Earth.

27 Sep 05; 20:34 hrs. 595 Polyxena shines at 12.8 mag and is 114 km in size. I’ve got it and a nearby 14th mag star rather quickly in the 12” at 98X thanks to a relatively sparse star field and a distinctive grouping of 10th mag stars to the S. Polyxena orbits Sol at 3.1 AU, and is presently 2.2 AU from Earth.

27 Sep 05; 20:38 hrs. 275 Sapientia is a 13.7 mag asteroid 121 km in size. I’ve got it and a nearby 14th mag star pretty quickly thru the 12” at 98X. Sapientia has a heliocentric radius of 3.2 AU and it is presently 2.3 AU from Earth.

27 Sep 05; 20:41 hrs. 563 Suleika currently lies 45’ W of a 4th mag star. It supposedly shines at 12.0 magnitude. I’ve got Suleika and a nearby 13.1 mag star thru the 12” at 98X, but there must be some local haze as everything looks a lot dimmer than it normally would. This 55 km sized asteroid orbits Sol at 2.4 AU and it’s now 1.5 AU from Earth.

27 Sep 05; 20:45 hrs. 701 Oriola is a 13.7 mag asteroid 46 km in size. I’ve sighted it and accompanying stars down to 13.7 mag using the 12” at 98X. Oriola orbits 3.1 AU from the sun and is currently 2.1 AU from Earth.

27 Sep 05; 20:48 hrs. 471 Papagena lies only 7° above the horizon – but fortunately from our cliff overlooking the ocean we have a completely unobstructed view to the S. I’m also fortunate in that this asteroid is a bright 10th mag, and is sitting in a sparse star field with several 10th mag stars for company. I’ve got it quickly in the 12” at 98X. Papagena is 139 km in size. It orbits Sol at 2.3 AU and it’s now 1.4 AU from Earth.

27 Sep 05; 20:52 hrs. 780 Armenia is a 13.2 mag minor planet 97 km in size. It orbits Sol at 2.8 AU and is now positioned 1.9 AU from Earth. It’s bracketed by some very bright stars in a sparse star field, and I’ve got it and some nearby slightly dimmer stars in the 12” at 98X without much strain.

27 Sep 05; 21:00 hrs. 1731 Smuts is a relatively dim 14.0 magnitude. Viewing thru the 12” I star hop in to its position and then increase magnification to 254X so that Ken Dore and I can both view it. Averted vision is required, but Smuts is pretty easy to see. This 56 km sized asteroid orbits Sol at 2.8 AU, and it is presently 1.8 AU from Earth.

27 Sep 05; 21:05 hrs. 300 Geraldina is a 13.8 mag asteroid 79 km in size. It’s traveling thru a very sparse star field, and there’s an 8th mag double star to the E that serves as a jumping off point for my star-hopping. I’ve got Geraldina and a 14.2 mag star just 2’ to the N using 98X in the 12”. This asteroid orbits the sun at 3.0 AU and it is now 2.0 AU from Earth.

27 Sep 05; 21:09 hrs. 403 Cyane is a 13.4 mag minor planet 51 km in size. It is currently 45’ W of a 5th mag star and its relatively high in the sky, making it a quick find using the 12” at 98X. Cyane orbits Sol at 2.9 AU and is presently 2.0 AU from Earth.

27 Sep 05; 21:14 hrs. 1139 Atami is a 13.1 magnitude Trojan now only 0.58 AU (54 million miles) from Earth. It’s high in the sky and I’ve got it thru the 12” at 98X very quickly by star hopping along a chain of 9th mag stars to the W. This 20.7 km sized asteroid orbits the sun at 1.56 AU.

27 Sep 05; 21:21 hrs. 89 Julia is a bright 9.7 mag minor planet 159 km in size. It represents one of the few low numbered asteroids that I haven’t yet viewed. Julia lies in a crowded star field with many 9th mag stars, and viewing thru the 12” at 98X it takes me a while to get oriented. Once I figure out that Julia IS one of the 9th mag “stars” the pattern falls into place and I can confirm the sighting. Julia orbits Sol at 2.1 AU. And it is now 1.3 AU from Earth.

27 Sep 05; 21:32 hrs. 43 Ariadne is an 11.1 mag asteroid that was my second prime target this evening, as it fills the lowest gap in my asteroid observing log. Ariadne sits in a sparse star field and it takes me quite a bit of time to sort out my fov thru the 12” at 98X. Eventually I manage to get myself oriented and confirm sighting Ariadne. Ariadne is a 65 km sized asteroid orbiting 2.2 AU from the sun. It is now 1.3 AU from Earth.

That’s the end of my observing list at about the same time that Ken does, so he picks a few DSOS for the 12”.

M51 is very low in the NE and almost completely wiped out by the Fall River sky glow.

The Veil Nebula is striking when viewed thru the 12” using a narrow band Orion UltraBlock filter on the Nagler 31.

M13 sucks you right into the core when viewed thru the 12” using 179X.

Mars is still low in the muck, and no detail is visible.

Andromeda is visible as a faint “star” when using averted vision. Man, this is a wonderful site.

We wrapped it up and were rolling home by 22:12.

Observations & conclusions:

Viewing 20 asteroids in 2 hours (without missing one) is doing pretty well, and attributable to the perfect conditions we were experiencing. The wind was very light from the North. The last of the summer people had packed it in, so there were no visible cottages with lights on. The Milky Way stood out brightly – almost as well as what we experienced at Arunah Hill.

Ken and I were both grateful for each other’s company. And I think that he enjoyed himself as much as I did.

God, am I dragging here on the day after. But of course it was worth it.

Pete 28 Sep 05