Look! Up in the sky!
It's a bird!
It's a plane!
It's Superman! Well, close. It's actually his newly "discovered" home star system.
"Rao," the star around which orbits Superman's fictional home planet of Krypton, has been "identified" by astrophysicist Neil deGrasse Tyson as LHS 2520, a dim red dwarf about 27 light years from Earth, in the contellation Corvus ("The Crow").
According to Slate, Tyson was approached by DC Comics about the possibility of him appearing in Action Comics as a scientist who helps Superman find Krypton.
Tyson did even better: he offered to find DC Comics an actual star that would fit the bill and give the comic book story a degree of scientific legitimacy. He consulted star catalogs and settled on LHS 2520 as a plausible stand-in for "Rao."
Unsurprisingly, this idea is not without problems. Though astronomers have identified hundreds of planets around other stars in recent years, none have been found around LHS 2520. Of course, planets that have blown up, like Krypton did, might not be detectable.
There's also the detail that if Krypton orbited LHS 2520 at a distance that gave it the 382-day year specified by Superman's writers, it would be really cold there ― hundreds of degrees below zero. The surface temperature of LHS 2520 is only about half that of our bigger, brighter, yellow Sun.
For the purposes of a comic book, though, LHS 2520 will do just fine.
Finding Krypton
Red dwarfs do not shine very brightly. Even those that are relatively close to earth, such as Barnard's Star, which is only six light years away, require a telescope to spot. LHS 2520, at 27 light years away, will require very dark skies ― no moon and as little artificial light pollution as possible ― and a telescope with a mirror at least six inches in diameter.
Without any optical aids, the closest star to "Rao" one can easily spot with the naked eye is Gienah, which comprises part of "The Crow's" wing. Gienah is a fairly bright star that should be visible even if you have heavy light pollution in your yard.
If you're in the western suburbs of Philadelphia, Gienah currently rises early in the morning and doesn't get far away from the glare of the city lights before it gets drowned by the glow of the rising Sun. Look for the irregular rectangle shape of Corvus "The Crow" to the south of brilliant Venus in the eastern predawn sky. Gienah is the uppermost star in the constellation at this time of year. If you extend your arm and cover Gienah with the base of your thumb, the location of "Rao" should be under your thumbnail.
If you're not an early riser, you'll need to wait for early spring for a decent chance to spot "Rao." It won't rise before midnight until mid-January, and it will be late March before it gets away from the city's light pollution at a decent hour. In early May, it will be a little less than halfway up the southern sky at about 10:30 p.m. each night.
That leaves plenty of time for you to put a telescope on your Christmas wishlist.
