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Terry's Occultation Page

 

 

Greeting from West Palm Beach

This month we have the rare treat of several Lunar Grazes that may be observed from within Florida. Therefore, this months occultation page will be in two parts. First, we will address Lunar Garzes. Second, we will address occultations of stars by asteroids.

Nearly a dozen Lunar Grazes will be observable from within Florida. Indeed, several may be observed from within Palm Beach County. Unlike an asteroid occultation which may be observer from anywhere within the shadow path, often an area several miles wide to over a hundred miles in width, Lunar Grazes require more precise planning with the observers occupying an area in width of about 100 meters to 1 or 2 kilometers. The idea is to measure the graze in such away as to be able to determine the profile of the mountains on the moon.

Don't forget, Daylight Savings time change on March 14th, so be sure to adjust the time in your planning. My picks for the best Lunar Graze events in the Palm Beach area are:

March 21, 2010

an 8.1 magnitude star with the event happening at about 02:04:22 UTC (Saturday, March 20, 9:04 PM local)

March 23, 2010

a 6.8 magnitude star with the event happening at about 00:20:22 UTC (Monday, March 22, 7:20 PM local)

March 23, 2010

an 8.7 magnitude star with the event happening at about 01:55:14 UTC (Monday, March 22, 8:55 PM local)

March 27, 2010

a 6.9 magnitude star with the event happening at about 03:09:26 UTC (Saturday, March 26, 10:09 PM local)

Most of these events are well after dark and within an hours drive of West Palm Beach. I will be away on travel the March 21, but hope to be here for the other events. The first March 23 event is early evening. But the star is bright enough that it should be doable. Planning is currently underway to plan observing the March 27 graze. If you would like to participate, please let me know.

View or download PDF of Lunar Grazes

Last month I announced that my pick for March would be a 172 mile wide asteroid, (13) Egeria on March 9th. This 11.8 mag asteroid will pass in front of 13.5 mag 2UCAC 19477665 at 05:45:49 in the morning on Tuesday, March 9th. I plan to attempt this event.

You will note in the table image a list of events that I plan to attempt. There are a total of seven occultations during which the shadows will pass directly over my house. It will be a very busy month. Note that a second occultation on Sunday, March 28, 2010 has attracted a total of eight observers. Three of us in Florida. This is a bright event involving an 11th magnitude star and should be doable with most of our portable telescopes. I would encourage those who can to plan to do this event. Be sure to have a good time source and a tape recorder to record the disappearance and reappearance of the star when (52) Europa occults 2UCAC 39108118. The local time is Sunday, 11:42 PM March 28th. If anyone would like to join me for the occultation, you would be welcome.




(Click to enlarge image)


Below is a map showing the path of the shadow and the location of all eight planned observers to include Redding South, in West Palm Beach. The thin green line is the center of the path. The two thin blue lines are the predicted left and right limits of the shadow. The pink lines are the limits of the 1st Sigma area. This event is ranked at 100%. Thus, if we have clear skies, and you can see 11th mag stars, this is an event you can do from home, or what ever observation site within the path of the shadow you choose. If you would like to have your site coordinated with in IOTA, just call and I will enter your observation site in Occult Watcher. Or, if you prefer you can down load the program and report your intention to observe.




(Click to enlarge image)


For those with an interest in chasing shadows there is an entire community of amateur and professional astronomers that daily coordinate worldwide to observe and report on occultations, IOTA. The International Occultation and Timing Association, where you can learn more about them, can be found here: http://www.occultations.org/

Two resources readily available to those in the Palm Beaches are the web pages maintained here http://www.poyntsource.com/New/Regions/Redding.htm and here http://www.hristopavlov.net/OccultWatcher/OccultWatcher.html

The first is a website updated each month by Derek Briet for amateur astronomers in the Palm Beaches. He list future asteroid and lunar events. His web products are created with Occult v4.

The second website is the home of Occult Watcher. This program is the one I use to create a list of potential occultations and mutual events that can be observed from my location, or near my location. It is a very easy to use program that has become essential for those wishing to chase shadows and coordinate their efforts with the larger community of observers.

If you have an interest in occultations, and would like help getting started, please feel free to contact me.

Now lets chase some shadows.

Terry - W6LMJ - 14.287



Terrence R. Redding, Ph.D.
Redding Observatory South, West Palm Beach, Florida
How do amateur astronomers learn?


American Association of Variable Star
Observers (AAVSO): RTN http://www.aavso.org/