The case of the disappearing star March 17, 2014Posted by aquillam in Astronomy, MichiganAstro, Urban Observing.
Tags: asteroid, citizen science, eclipse
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On Thursday, March 20 at 2:06 AM EDT, for observers in a narrow swath that happens to include New York City and Utica New York, and Kingston Ontario, The bright star Regulus will momentarily disappear. For those “in the know”, this won’t be much of a mystery. It’s actually an occultation by an asteroid.
To find out if you’re in the path, check out the map (and read more about this event) at read the Sky and Telescope article at http://www.skyandtelescope.com/community/skyblog/observingblog/Bright-Star-to-be-Blacked-Out-by-Faint-Asteroid-249327421.html
Even if you aren’t in the direct path, it may be worth observing. We don’t really know a lot about asteroid 163 Erigone. Is it oblong? A loose rubble pile? Surrounded by moons? You could help answer these questions. Observers from the east coast to the midwest and central Canada (including Ann Arbor!) are being asked to check out Regulus that morning. In fact, there’s even an app for citizen scientists to use to record and report your observations. For more on that, including a link to the app and a map visit the occultations.org site http://occultations.org/Regulus2014/
For a bit more on what we can learn, see my earlier post about the Regulus occultation. Or that link just above, which is where I got most of my information!
An Eclipse of Regulus, March 20, 2014 February 12, 2014Posted by aquillam in MichiganAstro, Urban Observing.
Tags: asteroid, astronomy, citizen science, urban_observing
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On March 20, 2014, a very rare event will occur. For a few people in a narrow band that includes New York City, Utica NY, Bridgeport CN, and Kingston ON, at around 2 in the morning, the bright star Regulus will disappear. Asteroid 163 Erigone will pass between observers and the star that night, and, just like a solar eclipse, anyone who happens to be in the shadow will see the star disappear. Asteroids move pretty quick though, and their shadows are tiny, so don’t blink or you might miss it! Luckily, Regulus is a bright star, so it’s usually visible even in pretty bad skies.
There’s a lot we can learn from this event too, and scientists are looking for your help! We don’t actually know a whole lot about Erigone. Observations of how long it lasts and where people were actually able to observe the occultation help scientists characterize the asteroid and its motion. Think about the shadow of a badly thrown football compared to the shadow of a well thrown tennis ball. Simply knowing where the shadow fell and for how long will tell scientists something about the shape of the asteroid and (if it’s not round) if it’s tumbling.
If you aren’t in the narrow path of the shadow, but aren’t too far away, you can still help. If Erigone has a moon, the moon’s shadow may be several hundred miles from the main shadow. You could be part of a very small group of people to discover that moon!
Additionally, it may be possible to learn about Regulus. Anyone who can do imaging or photometry can help measure how the light curve, which can be used to put limits on the diameter of star.
For a map of the path, and to find out more about how to make and report an observation, visit
Tags: asteroid, observing
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In case you wanted to try and watch the asteroid yourself, Sky&Tel has a nice article with a map. It’ll be pretty faint though, dimmer than magnitude 11 by the time we can see it in Ann Arbor. Definitely not an urban observing target.