Aldebaran Sails On / Crescent Moon Eyes Mercury And Venus Next

The crescent moon and its “companion,” Aldebaran, rise orange over Lake Superior this morning minutes before the occultation begins. Notice the peculiar shape of the reflection. Bob King

Mostly clear skies this morning made for a wonderful last occultation of Aldebaran till 2033. I stood along the shore of Lake Superior in Duluth and contemplated for a moment what that year might look like should I be fortunate enough to live so long. When the image of a man steadying himself with a cane flashed by, 2018 bonked me back to the moment.

The crescent moon rose squished like someone had tried to pinch the horns together; Aldebaran shined just below its lower left edge. I couldn’t see the star with the naked eye, but binoculars showed it along with some extra red coloration from low altitude. The moon, a beautiful cantaloupe orange, cast a dagger-like path across the water. The bright part on the left was the reflection from the sunlit crescent; the fainter, wider portion from the ghostly, earth-lit half of the moon.

Aldebaran reappears along the moon’s dark edge at 3:52 a.m. this morning from Duluth, Minn. Bob King

Through my telescope, air density and turbulence in the belly of the sky roughed up the images, turning Aldebaran into a flashing disco ball of red-and-green light. At 3:30 a.m. Central time, the star went pfft! behind the edge of the advancing moon. Just like that, the crescent stood alone and a little less lively for having lost its companion.

Closeup of Aldebaran seconds after it shot back into view. Bob King

21 minutes later, I eased back against the hood of my car, binoculars pressed to my eyes, and waited. I knew that within a minute Aldebaran would reappear along the dark, earth-illuminated lunar hemisphere. And it did, but instead of the star popping out from behind the edge, it looked more like the moon stepped out of the way. I’ve never had that impression before.

While it wasn’t an occultation for people living in Boston, Dan Dill created a wonderful composition of the close conjunction of Aldebaran with the moon framed by the cables of the Leonard P. Zakim Bunker Hill Bridge across the Charles River this morning. Copyright 2018 Dan Dill

Now, with the moon higher up and free of the horizon much, Aldebaran came instantly into view with the naked eye, shining in spectacular fashion as it kissed the moon’s dark limb. Dawn with its big crayola box colored the eastern sky red, blue, yellow and orange, but the star stubbornly refused to submit to the coming light. 45 minutes before sunrise I could still see it.

After an early rise for an astronomical outing, it can be hard to get back to bed, but not this time. Sleep occulted my busy brain nearly as fast as the moon blanked Aldebaran.

A pretty crescent rolls by Mercury and Venus this weekend. The Venus conjunction should be dramatic. Stellarium

The moon never sleeps. Come this weekend, a brand new, super-thin evening crescent slides just 2° above Mercury on Saturday and only a ½° from Venus for the western half of the country on Sunday evening. Observers in the eastern half will still see a close pairing, but moon and planet will be a little further apart at 1°.  How nice that all these great conjunctions are happening in the summer, when it’s easy to get outside.

4 Responses

  1. Kevan Hubbard

    Wish I’d seen the alderbaron moon one but was asleep then!ill be about 75 in 2033 ah well!however I did see the close conjunction twixt Venus and regulus plus mercury two nights in a row from two different countries!first time from Tbilisi,Georgia from an urban mountain top,then out my hotel window from Yerevan,Armenia,last night.

    1. astrobob

      Hi Kevan,

      We each get a little piece. Glad you got to see the conjunction! And we’ll only have to wait 5 years for the next series of Antares’ occultations to begin 🙂

    1. astrobob

      Thank you for your kind words, Marcos. I used a 100-400mm f/4.5-5.6 telephoto on a Canon 1DX, all in manual mode. ISO was 1600 with an exposure of either 0.8″ or 1″. To avoid vibration during the exposure I used the 2-second self-timer. The vertical photo was zoomed to 400mm, the others closer to 100-150mm.

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