Astronomy Israel: Aldebaran

Showing posts with label Aldebaran. Show all posts

Monday, July 30, 2012

Jupiter's Disappearing Act

One of the most beautiful celestial events I have seen in a long time occurred early on the morning of Sunday July 15th, and Israel was perfectly placed for it. The waning crescent moon occulted Jupiter and its four Galilean satellites over the skies of Mitzpe Ramon. An occultation occurs when one astronomical body passes in front of another and blocks its light for a period of time. In this case the moon, at about 230,000 miles distant from earth that morning passed in front of Jupiter and its moons, about 526,963,352 miles distant, a ratio of 2,291 in distance! The moon approached Jupiter, slowly engulfed two Jovian satellites to its right, then the planet, then the two remaining Jovian satellites, and reversed the process about an hour later. The moon and Jupiter were in a very rich area of the sky that night, in the constellation Taurus with the Hyades star cluster nearby, along with the bright, red star Aldebaran and many other stars nearby that were only visible in the telescope.

Because such events are so beautiful and memorable, I had called for a star party to begin at 3:00AM that morning. Despite the early hour, about 30 people showed up, some from as far away as Gush-et-Zion, along with many from Mitzpe Ramon. I had set out 4 telescopes and a pair of giant binoculars, so we were well provisioned for the night. The weather was warm, the sky clear, and the desert winds that blow most of the night had quit for the evening, as the temperature in Machtesh Ramon and on the rim, where we were, came into equilibrium.

The first photo shows the rich star field that the moon was entering as it began to engulf Jupiter. Jupiter is hidden in the overexposed glow of the moon which was necessary to show some of the dimmer stars.

The rich star field around Jupiter shows the Hyades star cluster below and to the right of Jupiter with the brilliant red supergiant star Aldeberan directly below the moon. Many other stars are shown in the field and must have also been occulted by the moon, but little mention was made of them in pre-occultation summaries of the event. Jupiter is hidden in the moon's glare near the bright limb. Photo: Ira Machefsky

Jupiter and its four Galilean moons about to be occulted by the moon, along with other bright stars in the vicinity. In order from the very left: Callisto, Ganymede, Jupiter, Io, Europa, Moon. Photo: Roy Brown

Jupiter about to be occulted by the moon. Photo: Roy Brown

Jupiter, preceded by Io and Europa, emerges from behind the moon. Photo: Roy Brown

Jupiter and all four of the Galilean moons emerge about an hour later. Another star, identity unknown, to the left of the moon is just a few minutes away from being occulted. Photo: Roy Brown

As the moon moved away from Jupiter and its moons, the tableau took on the appearance of some vicious primitive weapon, the scythed blade of the moon being held by the spindle of Jupiter and its moons.

The vision was made all the lovelier by the appearance of Venus on the scene, just before sunrise. Venus was shining near its maximum magnitude of -4.7, a beacon below Jupiter and the moon in the gathering light of day.

Venus rises brightly below the crescent moon and the exiting Jupiter as Aldeberan shines above and to the right of the Morning Star. Photo: Ira Machefsky

Finally, a scene that few got to see: Sunrise at our observing location, the rim of the world's largest erosion crater, Machtesh Ramon:

Sunrise on Machtesh Ramon, after the Jupiter occultation. Photo: Ira Machefsky

Wednesday, July 4, 2012

Moon to Occult Jupiter in Rare July 15th, 2012 Event

A rare, major and hugely memorable event will occur early in the morning of Sunday, July 15th when the moon passes in front of the planet Jupiter (astronomers call this an "occultation") blocking it from view for about an hour. As the moon then moves eastward in its monthly orbit around the earth, Jupiter will be uncovered about an hour later. This event is not receiving much publicity because it will not be visible from the US, but the Middle East and Africa will have a front row seat. In addition to Jupiter, the four bright moons of Jupiter, the "Galilean satellites", will also be occulted in the course of this event. This is a very rare event, although as of this writing I don't know when the next occultation of Jupiter will be visible from Israel.

The moon, Jupiter and Venus as seen on the morning of June 17, 2012, rising above Mitzpe Ramon. The moon just missed Jupiter on this pass. On the early morning of July 15th at 4:01AM IDT the moon will pass in front of Jupiter, occulting it.

The tableau in the east in the early morning sky is already quite stunning. Jupiter, with Venus below it, shine brightly like beacons with the Pleiades star cluster above and the Hyades star cluster below, and ruby-red star Aldeberan (Alpha Tauri) set like a jewel at the bottom. Really, this alone is worth rising early to see. But on the morning of July 15th, starting about 3:30AM, this tableau will rise in the east with the waning, crescent moon accompanying the entourage. Beginning at 4:01AM, the moon will cover Jupiter and it's Galilean satellites over the course of a few minutes, blotting them out of the sky. About an hour later they will pop out from behind the moon one by one. All the angels will sing, "Hosannah in the Highest!"

How the sky will look on the morning of July 15, 2012, 4:01AM IDT, from Israel, just after the occultation begins. This star map doesn't even begin to hint at the glory in the east at this event.

These occultations are memorable events just when seen with the naked eye. The proximity of so many bright heavenly bodies near each other is one of the most beautiful sights the sky has to offer. Through any kind of optical instrument the grandeur is even greater. You will need at least binoculars to see the Galilean satellites occulted. A telescope, of almost any size, will show much more, including the cloud-striped disk of Jupiter as it slides behind the bright, crater-scared rim of the moon and reappears from behind the dark side of the moon. I remember every occultation I have ever observed and treasure them as my dearest astronomical memories. You don't have to be in Miztpe Ramon to see this, or even have especially dark skies. But you will need a very clear eastern horizon, since all of these objects will have just risen about 30 minutes before the occultation begins.

An occultation of Jupiter by the moon. Animated gif by Don Parker.

This event will occur low in the east starting at 4:01AM IDT on Sunday morning July 15th and the occultation will end about an hour later, close to sunrise. I will be out all night with my telescopes and binoculars and all are welcome to join me, no cost. This will be an open star party. I hope other amateurs will join with their telescopes. As of this writing I plan to be at the last JNF forest on the left of the road heading up to the Wise observatory, about 1 KM from the Wise observatory on the plateau overlooking Machtesh Ramon. There is a turn-off from the road there that leads to a short dirt road that goes around the forest to where I will be. Check back for any last minute changes.

"Ira" is where the Starman of Mitzpe Ramon currently plans to be on the morning of July 15th in Mitzpe Ramon.

Good luck viewing and remember to "Keep on lookin' up!"

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Sunday, January 16, 2011

A Four Star Night

We had the pleasure of hosting Katherine and Evan last Wednesday night under a first quarter moon. Jupiter and Uranus were still visible in the same wide-angle telescopic field and continue to make an impressive sight. People are just amazed to find out that while visible near each other in a line from earth, Uranus is 1.4 billion miles farther away than Jupiter.

The moon, although bright, did not interfere too much with our observations and made a splendid spectacle itself in the telescope. We had a good view of the Lunar Alps and Piton in Mare Imbrium.

We tried to split the Pup again (drum roll), but failed (raspberry). This is still at the top of our observing list this season. Who will be the lucky guests to be counted among the few on earth who have split the Pup? Only time will tell.

Evan was a fast learner and got three stars for being able to answer all of my questions on night vision and the position of the North Star from various latitudes on Earth. Katherine got a gold star for quickly identifying star colors, especially the Red Giants Betelgeuse and Aldebaran. She also called Capella's yellow tint immediately. A four star night! (Note to self: must get gold stars to paste on people's astronomy portfolios.)

Evan is a medical student at Ben Gurion University of the Negev and Katherine is a writer for Time Out Israel. Maybe she will write something nice about us. Could we have a picture, too? :-)