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Ephemeris Extra – Occultation of Aldebaran visible from the Upper Peninsula and the tip of northern lower Michigan

July 8, 2018 Comments off

In the early morning hours of July 10th the very northern part of the IPR listening area will have a chance to see the last occultation of the bright star Aldebaran for at last 15 years. An occultation is where the Moon in this case passes in front of or occults a planet or a star. In astronomy occult means to hide. The event is an occultation. There is no black magic involved. It will be a grazing event, with Aldebaran popping in and out of view at the mountains and valleys at the southern edge of the Moon along a line running south of Mackinaw City and across the eastern tip of the Upper Peninsula.

Occultation of Aldebaran map

The Straits of Mackinac area showing the green southern graze line of the Occultation of Aldebaran. Credit Map Google Earth, Graze line by Occult 4.

It’s a clear miss for the Interlochen area, with the star skirting the Moon at it’s 5 o’clock position. The time of the event will be near 4:38 a.m. with the maximum time of the event increasing from west to east at nearly 2,000 miles an hour. At that time the Moon and Aldebaran will be low in the east-northeast and only 7 degrees above the horizon.

Moon and Aldebaran finder chart

Location of the Moon and Aldebaran in the sky at 4:38 a.m. July 10, 2018 from the Interlochen/Traverse City area.

More information on this occultation from Sky and Telescope is here.
This will be the last occultation of Aldebaran visible from around here for the next 15 years. However starting in 5 years there will be a monthly series of occultations of the bright star Regulus, and the next year a series of occultations of the star Spica will begin. That’s just for the Moon with bright stars. The Moon occults many dimmer stars a month. A very important field of occultations is the observation of occultations of asteroids and Kuiper belt objects to discover their size, shape, any satellites and whether they have rings. Go to the International Occultation Timing Association https://occultations.org for more information.

Hat tip to Jerry Dobek, Director of the Joseph H. Rogers Observatory

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12/29/2017 – Ephemeris – Last occultation of the star Aldebaran by the Moon is tomorrow night

December 29, 2017 1 comment

Ephemeris for Friday, December 29th. The Sun will rise at 8:19. It’ll be up for 8 hours and 51 minutes, setting at 5:10. The Moon, half way from first quarter to full, will set at 5:08 tomorrow morning.

We have one last cool astronomical event that can be seen from here in 2017. Of course, weather permitting. Tomorrow night the Moon will occult the bright star Aldebaran in Taurus the bull from 6:17 to 7:17 p.m. I’m not dabbling with the black arts here, even though I’m using the Occult 4 program to find it. In astronomy occult is a verb meaning to hide, and the event is called an occultation. The Moon will appear to move in front of, or hide the star Aldebaran. At 6:17 p.m. Aldebaran will disappear at the dark edge of the Moon at its 8 o’clock position. Binoculars will be needed to spot the star against the glare of the bright Moon before the event. Aldebaran will pop out from behind the Moon at a bit above the 3 o’clock position at 7:17 p.m.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Occultation visibility map

Occultation visibility map for the occultation of Aldebaran by the Moon for us in the Unites States, the early evening of December 30, 2017. Created using Occult 4 by IOTA.

Occultation start

Occultation start 6:17 p.m. December 30, 2017. as seen from the Grand Traverse area of Michigan. Actual times may vary depending on your location. Created using Stellarium.

Occultation end

Occultation end 7:17 p.m. December 30, 2017. as seen from the Grand Traverse area of Michigan. Actual times may vary depending on your location. Created using Stellarium.

Note the times are for the Traverse City/Interlochen area. It will vary by a few minutes for northern lower Michigan.  The position angles of the entrance and exit points of Aldebaran will also be different.

Otherwise use a planetarium program like Stellarium to preview the event. However, set the program for topocentric coordinates. In Stellarium that’s in the Configuration window, Tools Tab and check the Topocentric coordinates box. Topocentric coordinates are the apparent positions for your location on the Earth. So also make sure your location is correct. The geocentric conjunction of the two bodies will be December, 31, 0:49.2 UT, so it will occur after midnight on the morning of December 31st for locations in northern Europe and Asia.

Program Note

The January preview will be an Ephemeris Extra post on December 31st.

 

 

11/05/2017 – Ephemeris Extra – There will be an Occultation of Aldebaran tonight*

November 5, 2017 1 comment

This posting will not be broadcast.

* Or tomorrow morning, depending where you are.

Ephemeris extra for Sunday, November 5th. The Sun will rise at 7:25. It’ll be up for 10 hours and 5 minutes, setting at 5:25. The Moon, 2 days past full, will rise at 7:01 this evening.

Tonight just after 8 p.m. the bright star Aldebaran will disappear at the left edge of the Moon. Aldebaran is angry red eye of Taurus the bull. The star will reappear at the dark upper right edge of the Moon. Start looking at 8 p.m. or before. Use binoculars or a small telescope to spot the star against the glare of the bright Moon. The star is nowhere as bright as shown in the illustrations below. Star appearances and disappearances appear instantaneous, unlike what the illustrations show.

Aldebaran Occultation begins at 8:07 p.m. EST (1:07 UTC Nov 6th)
Aldebaran Occultation ends at 9:00 p.m. EST (02:00 UTC Nov 6th)

Note the times are for the Traverse City/Interlochen area. It will vary by a few minutes for northern lower Michigan.  The position angles of the entrance and exit points of Aldebaran will also be different.

Otherwise use a planetarium program like Stellarium to preview the event. However, set the program for topocentric coordinates. In Stellarium that’s in the Configuration window, Tools Tab and check the Topocentric coordinates box. Topocentric coordinates are the apparent positions for your location on the Earth. So also make sure your location is correct. The geocentric conjunction of the two bodies will be November 6, 2:42.9 UTC, so it will occur after midnight on the morning of November 6th for locations in northern Europe and Asia.

Addendum

Occultation Map

Occultation Map for the occultation of Aldebaran by the Moon . Credit Occult 4 program from IOTA.org.

Occultation start

Aldebaran at the start of the occultation at 8:07 p.m. for the Traverse City/Interlochen area. Created using Stellarium.

Occultation end

Aldebaran at the end of the occultation at 9:00 p.m. for the Traverse City/Interlochen area. Created using Stellarium.

11/03/2017 – Ephemeris – The Sun is the topic at tonight’s GTAS meeting

November 3, 2017 Comments off

Ephemeris for Friday, November 3rd. The Sun will rise at 8:23. It’ll be up for 10 hours and 5 minutes, setting at 6:28. The Moon, 1 day before full, will set at 8:35 tomorrow morning.

This evening the Grand Traverse Astronomical Society will hold its monthly meeting at the Northwestern Michigan College’s Rogers Observatory at 8 p.m. with a program featuring member Don Flegel in a talk about the Sun. Don’s the keeper of our solar telescope and wanted a good excuse to learn more about the Sun, so he decided to study up and give this talk. That’s how I do it.

After the talk, at 9 p.m. there will be a star party, if it’s clear, to view the heavens including the Moon. The observatory is located south of Traverse City, on Birmley Road between Garfield and Keystone roads.

It’s time to change our clocks again at 2 a.m. Sunday. Turn your clocks back one hour. That’s Fall Back one hour for a bit of extra sleep.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addenda

Don Flegel at Fishtown

Don Flegel, in the foreground, with the society’s solar telescope assisting a person viewing the Sun at he Leland Heritage Festival 2017 at Fishtown.  Man in the background in the blue cap is Gary Carlisle.  The telescope in the middle is mine.

Occultation of Aldebaran by the Moon Sunday Night

Occultation Map

Occultation Map for the occultation of Aldebaran by the Moon . Credit Occult 4 program from IOTA.org.

For the Traverse City/Interlochen area:

Aldebaran Occultation start 8:07 p.m. Nov 5th (01:07 UT Nov 6th)
Aldebaran Occultation end 9:00 p.m. Nov 5th (02:00 UT Nov 6th)

I’ll have an Ephemeris Extra posting, Sunday November 5th with more information.

10/13/2017 – Ephemeris – The bright star Regulus dips behind the Moon Sunday morning

October 13, 2017 1 comment

Note:  The original program recorded for this day was erroneous in the timing and appearance of this event.  Occurring about an hour later than reported here.  The Interlochen personnel may or may not replace the original program with the one below.  Also those who downloaded the audio from ephemeris.bjmoler.org before late Thursday night may have downloaded the incorrect mp3.

Ephemeris for Friday, October 13th. The Sun will rise at 7:55 a.m.. It’ll be up for 11 hours and 5 minutes, setting at 7:00 p.m. The Moon, 1 day past last quarter, will rise at 2:08 tomorrow morning.

On Sunday morning the Moon will pass in front of, or occult the bright star Regulus, the brightest star in Leo the lion. This will happen as morning twilight starts. Regulus will disappear at the left edge of the crescent Moon at around 5:47 a.m. A telescope or binoculars may be needed to spot Regulus. Go out at least 5 or 10 minutes early to make sure you can spot the star. Regulus will reemerge at 6:25 at the 11 o’clock position on the dark part of the Moon. Earth shine on the night side of the Moon may be bright enough to see its dark edge. Observers west of us in the United States except the northern most states west of Minnesota will also get a view. Those in specific locations in the northern tier of states will get to see Regulus just graze the north edge of the Moon.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Occultation start

Occultation of Regulus by the Moon disappearance at around 5:47 a.m. for northern Michigan. Created using Stellarium.

Occultation end

Occultation of Regulus by the Moon reappearance at around 6:25 a.m. for northern Michigan. Created using Stellarium.

Occultation Map

Map showing the locations where the occultation of Regulus will be visible. For the area bounded by heavy lines the occultation will occur at night. Click on image to enlarge. Credit: Occult4 by IOTA.

09/12/2017 – Ephemeris – The Moon will hide the bright star Aldebaran after sunrise this morning

September 12, 2017 Comments off

Ephemeris for Tuesday, September 12th. The Sun will rise at 7:18. It’ll be up for 12 hours and 40 minutes, setting at 7:58. The Moon, 1 day before last quarter, will rise at 12:13 tomorrow morning.

This morning during daylight at around 8:40*. the bright star Aldebaran will disappear behind the Moon. Binoculars or a small telescope can be used to spot Aldebaran, the bright star in the constellation Taurus the bull’s eye. Taurus and the rest of the winter constellations are visible before sunrise. The sky needs to be absolutely clear to be able to spot the event. The star will be seen to approach the bright side of the Moon. The star will reappear around 9:53 a.m.* on the dark western edge of the Moon. These events are called occultations. They come from the word occult, which means hidden. In actuality the solar eclipse of three weeks ago was a spacial case of an occultation for those in the path of totality.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

* The disappearance and appearance times for Aldebaran are within a couple of minutes for Western Michigan.  For other locations in the occultation path Stellarium will give pretty good times for the events by modeling the occultation as I did below.  Like a solar eclipse where you are determines the timing of the event.

Addendum

Occultation map

Map of where the occultation is visible. For the area bounded in red, the occultation is visible in the daytime. Credit: Occult4 by IOTA.

Position of the Moon in the sky

Position of the Moon in the sky near the start of the occultation, 8:35 a.m. September 12, 2017. Created using Stellarium.

Aldebaran and the Moon at 8:35 a.m.

Aldebaran and the Moon at 8:35 a.m. September 12, 2017. Created using Stellarium.

Aldebaran reappearing from behind the Moon

Aldebaran reappearing from behind the Moon at 9:53 a.m. September 12, 2017. Created using Stellarium.

 

03/03/2017 – Ephemeris – Astronomy talk and star party tonight and the occultation of Aldebaran tomorrow night

March 3, 2017 Comments off

Ephemeris for Friday, March 3rd.  The Sun will rise at 7:15.  It’ll be up for 11 hours and 17 minutes, setting at 6:33.  The Moon, 2 days before first quarter, will set at 12:36 tomorrow morning.

Tonight the Grand Traverse Astronomical Society will present a talk by Becky Shaw on international observatories at 8 p.m. at Northern Michigan College’s Rogers Observatory.  Also tonight at the observatory, there will be viewing of the Moon and other wonders of the March skies.  Tomorrow night shortly after 11 p.m. the bright star Aldebaran in Taurus the bull will be covered or occulted by the Moon for about half of the IPR listening area.  It will be seen by observers south of a line from Leland to south of Mancelona centered on 11:13 p.m.  The farther south one is the longer the occultation will last.  Start looking by 11 p.m. and check my yesterday’s blog post for more information.

Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.