March 17, 2014
Citizen Scientists Wanted To Observe Asteroid Blot Out A Star
Lawrence LeBlond for redOrbit.com - Your Universe Online
Millions of Americans may be able to catch a space rock darkening the night sky this Thursday as the brightest visible star vanishes before our very eyes.
Once you find Regulus, keep a steady gaze on it and you will almost assuredly be witness to one of the grandest phenomena one can witness with the naked eye. The 45-mile-wide asteroid 163 Erigone will pass between Earth and Regulus just after 2 a.m. on Thursday and could blot out the star for as long as 14 seconds during its “occultation.”
According to Sky & Telescope Magazine’s Alan MacRobert, the occultation – which comes from the Latin word meaning ‘hide’ – will be visible for more than 20 million people in the New York metropolitan area and parts of Long Island, New Jersey, upstate New York, Connecticut and Ontario. He said that the exact time will vary depending on location, but New Yorkers should be able to witness the event at around 2:06 a.m. on Thursday, March 20. Farther north, the event should take place about a minute or two later.
While the event will easily be visible to the naked eye, MacRobert said that anyone with amateur sky gazing tools can help be a part of the history-making event.
“You can give one additional data point for determining the character of this asteroid that will be known for all time and history," he told USA Today’s Traci Watson, adding that anyone can provide useful information, be it with a stopwatch, a video camera, or a digital SLR camera. But, he added, data points from people with no equipment at all can be just as useful.
Asteroids constantly block out stars every night. But the difference between most space rocks and 163 Erigone is that people generally need a telescope to be able to view such occultations. And during most occultations, asteroids are too small, too fast or too far away to be easily observable.
As well, relatively few stars are bright enough to be seen with the naked eye, according to Steve Preston, president of the International Occultation Timing Association (IOTA), which is asking citizen scientists to observe and time a “rare and beautiful astronomical event.”
Preston told USA Today that only eight occultations of stars visible to the naked eye have been observed in the USA since the 1980s.
Furthermore, this is the first time in history that an occultation of such a bright star by an asteroid has been predicted to cross such a heavily populated area.
"I've been using a telescope to go after asteroid occultations of really faint stars for ages. I never thought we'd get one in my life for a star this bright and easy," said MacRobert.
Erigone orbits the sun between Mars and Jupiter and does not come close to Earth, according to Jose Luis Galache, an astronomer with the Minor Planet Center, which tracks space rocks. During the occultation, viewers should see the star Regulus wink out, then reappear. Anyone who times the event can share their data with IOTA, which will use the collected data to calculate the asteroid’s shape and size to learn more about Regulus itself.
“A major star winking out like this? It's worth catching if you can," says Sky & Telescope assistant editor Camille Carlisle. She'll be traveling to watch the event with friends in upstate New York.
Skywatchers are also descending upon New York from as far away as Germany to try and catch a glimpse of a winking star. As well, local astronomers are planning to take to NYC’s bars and night clubs to encourage late-night patrons to step outside and look up. IOTA has developed a free smartphone app to help people time the passage of 163 Erigone. The group will also post recommendations on its website of the locations that will most likely have clear enough skies to witness the event.
The early forecast for most of the region is cloudy, but Preston said he plans to make the trip from Seattle to NY in hopes of seeing the event if there is even a chance of clear sky.
"This is a very rare event," he told Watson. "[It] may well be the only chance in my lifetime to observe an occultation of a first-magnitude star.”
For those who are not near the path or cannot make it to the show, it should not stop them from going outside and partaking in the event as well. People everywhere from South Carolina to Nova Scotia are encouraged to go out and watch Regulus during the critical minutes and report whether or not it vanishes.
The reasoning behind this is simple: there could be a chance that Erigone is being accompanied by a satellite asteroid, which has been observed in other large asteroids. If there is such an asteroid following in 163 Erigone’s footsteps, then it too could make a “secondary occultation” but in a different territory of the night sky.
Whether you are near or far from the path, step out from just before 2 a.m. until around 2:12 a.m. (EDT) for a chance a being part of a history-making event. All participants are encouraged to report their findings to IOTA whether a disappearance is seen or not.