Cbserving report of the Moon and the Pleiades
- On March 20th, the first day of spring, the Moon passed just to the
southwest of the Pleiades from my observing location. I observed them using
the TMB 130mm f/9.25 apo refractor on an alt-az mount. The skies were partly
cloudy and the seeing generally fair.
At low power using a 56mm 2" Meade Super Plossl the Moon and the cluster
easily fit into the same field of view. It was a very pretty sight. Using
TMB 40mm and 30mm 2" Paragons more detail was visible and the contrast was
higher, but I could no longer see the entire cluster.
With the TMB 100 16mm and 9mm eyepieces there was nice detail visible in the
craters Theophilus and neighboring crater Cyrillus (Rukl map #46) near Mare
Tranquillitatis. For example in Theophilus the walls had a terraced
appearance, and in the interior two elongated peaks were visible near the
center as well as two smaller peaks that looked like a double star. Cyrillus
showed also two elongated peaks. I then swung the telescope over to observe
Mars, however the high clouds and fair seeing reduced the finer detail.
Observing the Moon pass near the Pleiades and then Mars reminded me of an
occultation of the Pleiades by the Moon I observed back on September 2,
1988. I was using a different telescope at the time with eyepieces including
the 56mm Meade and a 35mm 2" Clave Plossl. During that occultation it was
interesting to watch as a star approached the sunlit portion of the Moon and
then disappear behind it. Later it would pop back into view from behind the
dark limb. Then, like now, Mars was visible in the night sky. However it was
a much more favorable opposition then as it reached a diameter of 23.81".
Even though Mars reached a diameter of 25.11" in 2003 it was much lower in
the sky, so the seeing was much better during the 1988 opposition.