Solar-Like Star Recognized Because the Potential Supply of the Wow! Sign
The Huge Ear Radio Telescope in Delaware, Ohio, was disassembled in 1998 having operated for over 30 years. It was changed by a golf course. Huge Ear was by no means the world’s largest radio telescope, nor its most delicate. However Huge Ear nonetheless made one of the vital well-known observations within the historical past of astronomy, one which until at the present time has by no means been defined.
All through the Seventies, Huge Ear looked for indicators from extraterrestrial civilizations. And on Aug. 15, 1977, it discovered one — a robust, intermittent sign lasting for 72 seconds, that stood out from the background noise like a searchlight.
The crew shortly dominated out a terrestrial origin or a broadcast from a satellite tv for pc. Nonetheless, the sign was so highly effective and weird that Jerry Ehman, the astronomer who analyzed the information print out, annotated the sign with the phrase “Wow!”.
The director of the observatory, John Kraus, later gave an in depth account of the remark: “The WoW” sign is very suggestive of extraterrestrial clever origin, however little extra may be stated till it returns for additional examine,” he wrote, in a letter to the astronomer Carl Sagan.
The Huge Ear crew continued to watch the identical a part of the sky, as have others, however the Wow! sign by no means returned. Nor has something prefer it been noticed in every other a part of the sky.
Kraus and others have even looked for stars that may very well be the supply of the sign: “We checked star catalogs for any sun-like stars within the space and located none,” wrote Kraus. To at the present time, the Wow! sign stays unexplained and unrepeated.
Which is why the invention this week of a possible supply is important information. The discovering is the results of some intelligent sleuthing by an newbie astronomer and the creation of a superb new 3D map of the galaxy.
First, some background. Again in 2013, the European Area Company launched the Gaia house observatory to map the night time sky — to find out the place, the space, and the movement of stars with unprecedented accuracy. To date, Gaia has mapped some 1.3 billion stars, permitting astronomers to start creating essentially the most detailed 3D map ever manufactured from our galaxy. The mission is anticipated to proceed till 2024.
Gaia’s new star map has considerably improved our understanding of the galaxy and the celebrities inside it and this gave newbie astronomer Alberto Caballero an concept. The Gaia database is now considerably extra detailed than the star catalog that John Kraus studied within the Seventies. Maybe the brand new database may reveal the supply of the Wow! sign, he reasoned.
(Credit score: Huge Ear Radio Observatory and North American Astrophysical Observatory)
So Caballero repeated the search, in search of Solar-like stars among the many 1000’s which were recognized by Gaia on this area of the sky. By Solar-like, he means stars that share the identical temperature, radius and luminosity
The search returned only one candidate. “The one potential Solar-like star in all of the WOW! Sign area seems to be 2MASS 19281982-2640123,” says Caballero. This star sits within the constellation of Sagittarius at a distance of 1800 light-years. It is the same twin to our Solar, with the identical temperature, radius, and luminosity.
In fact, Caballero’s work doesn’t imply that 2MASS 19281982-2640123 should have been the supply. He factors out that there are various stars in that area of the sky which are too dim to be included within the catalog. One among these may very well be the supply.
(Credit score: PanSTARRS/DR1)
And there are some 66 different stars within the catalog that Caballero recognized as potential candidates however with much less sturdy proof. These match the Solar’s temperature however information about their luminosity and radius is at present incomplete. So future information releases from Gaia and different mapping initiatives may but reveal them as matches.
However for the second, 2MASS 19281982-2640123 is our greatest wager and a very good candidate for future examine. Caballero says an apparent purpose could be to search for indicators of exoplanets orbiting this star. It is also prioritized for examine within the radio a part of the spectrum.
Within the meantime, astronomers may amuse themselves by discovering a friendlier title for 2MASS 19281982-2640123. Maybe throughout a spherical of golf on the course that now sits on the positioning of the Huge Ear radio observatory.
Ref: An Approximation to Decide the Supply of the WOW! Sign: arxiv.org/abs/2011.06090