Observing log of 9 Mar 05
Tonight’s the Backyard Astronomy class will be doing its thing in the backyard. The temperature is only 20° as I set the 12” scope out for cooldown at 16:30.
I’ve talked to the neighbors and they’ve turned off exterior lights. By 18:30 I’m out starting alignment. Mark & Jen arrive early and start setting up their ETX125. My initial alignment stars for polar mount are Capella and Regulus. But I subsequently sync on Sirius, Betelgeuse, Rigel and Procyon to get the scope dead on.
19:00 The scope is on Saturn using 97X as Ryan, Linda, Charles and Diane arrive. After everyone’s had a chance to view at low magnification the wind dies a bit and I’m able to increase magnification to 179X. At the higher magnification there’s quite a bit visible (Titan, Dione, Rhea, Enceladus, Tethys, the Cassini division and surface banding). Everybody views with a moon location chart and identifies moons and features.
19:20 At first I couldn’t find comet C2004/Q4 Machholz in the giant binoculars. But after locating it with the scope’s computer we can view it in the binocs. Machholz has faced to mag 6.5 and is pretty darned faint now. A tail is no longer visible.
19:30 We next view M42 (the Orion nebula) at 97X thru a narrow band filter that enhances the contrast. And after that the scope swings to M44 – the Beehive cluster. By now everyone but Mark has ducked into the house at least once to warm up.
The double cluster in Perseus is very bright tonight. Viewed at 97X, we slewed back and forth from one cluster to the other.
Galaxies M81 and M82 just about squeeze into the fov of my Nagler 31 at 97X. After everyone’s viewed these 2 objects 12 million LY distant I put the scope on M45 – the Pleiades (or the 7 sisters). Views of the Pleiades are better thru Mark’s wider field of view setup, and are even better yet in the Giant Binocs.
At around 20:20 I put the scope on asteroid 13 Egeria. But can’t find it. Eventually, later in the evening I will locate it. The cold is numbing my mind as I’m at a loss as to what to view next. So at Diane’s suggestion we wrap the class up a bit early so that folks can go home and thaw out.
9 Mar 05; 20:54 hrs. I started my search for asteroid 470 Kilia at the termination of class, and Ryan stayed around a bit, as did Mark and Jen. They were all able to star hop into the location of this 13.4 magnitude minor planet, but Ryan left before I increased magnification from 97X to 179X. At the higher magnification Kilia was relatively easy to view with the 12” using averted vision. Before leaving, Mark and Jen both observed it by using averted vision. Kilia is approximately 28 km in dia. It orbits the sun at 2.3 AU and is now 1.4 AU from Earth.
9 Mar 05; 21:21 hrs. Asteroid 1069 Planckia is 13.5 magnitude. Usually with the 12” at 97X this is a strain, but I’m seeing very well right now and pick up and pick up this 43 km dia minor planet by star hopping in from the E. Planckia orbits the sun at 2.8 AU and is now 1.9 AU from Earth.
9 Mar 05; 21:40 hrs. Asteroid 231 Vindobona is a faint 13.7 magnitude. But the sky is at this moment perfect, and I’m seeing a nearby confirmation star that’s only 14.4 mag. That may be the faintest I’ve ever observed. This minor planet was observed thru the 12” at 97X after star hopping in from the W. Vindobona is 85 km in size. It orbits Sol at 3 AU, and is presently 2 AU from Earth.
9 Mar 05; 21:48 hrs. 130 Elektra shines at 12.4 magnitude. I found it with the 12” at 97X by star hopping in from a bright star pattern to the NE. Elektra is 189 km in size. It orbits a relatively distant 3.4 AU from the sun, and is presently 2.5 AU from Earth.
9 Mar 05; 22:26 hrs. Asteroid 753 Tiflis is a very dim 13.8 magnitude. Its located close to a 9th magnitude star and there’s an easy to identify pattern to the NE. But it is only until I put the 15mm eyepiece into the 12” that I can see Tiflis. I’m observing two nearby 13.3 and 13.8 stars fairly easily at this point, but not seeing a 14.4 mag star just to the W of the 9th mag star, and can’t see a 14.7 mag star somewhat below Tiflis. Tiflis is currently 1.5 AU from Earth and is orbiting the sun at a distance of 2.4 AU. The assumed asteroid diameter is 60km.
9 Mar 05; 22:03 hrs. Asteroid 13 Egeria is a brilliant 10.1 magnitude. And its brightness is what made it hard to identify, as I took it to be a bright star, and the star pattern didn’t match my chart. Egeria is 215 km in size, and it orbits 2.4 AU from the sun. It is presently 1.5 AU from Earth. Viewed at 97X thru the 12”.
9 Mar 05; 22:08 hrs. 69 Hesperia is a bright 10.7 mag minor planet that I saw instantly thru the 12” at 97X. It appeared to be a double star, along with a second set of nearby doubles. Hesperia is 143km in size. It orbits the sun at 2.6 AU and is presently 1.6 AU from Earth.
22:45. Just as I’m closing in on 12.6 mag Roma the clouds shut me down. So I swing the scope onto Jupiter. Even at 97X the atmosphere this low is roiling and the planet image is moving about. 4 Galilean moons and lots of banding are visible, but no GRS.
It’s down to 17°F as I pack it in for the night.
Conclusions and lessons learned.
I did a relatively poor job in explaining to the class details on objects being observed. This was an oversight. But maybe it was due to a mind-numbing cold?
Extreme cold weather is very tough to work in. But in RI you take the clear sky however you can get it.
Can’t figure out why I was seeing faint objects so easily for a while.
Pete