Tuesday, May 23, 2017

Latest Dimming of KIC 8462852 Similar to Previous Ones, Says Tabetha Boyajian

Star KIC 8462852 in infrared (2MASS survey) and ultraviolet (GALEX). Credit: Infrared: IPAC/NASA, Ultraviolet: STScI (NASA)

Yale University astronomer Tabetha Boyajian, who led the team that first detected strange behavior of the star KIC 8462852 (nicknamed “Tabby’s star”) revealed that the latest dimming of this star is similar to the ones previously observed.

In late 2015, Boyajian’s team reported an unusual dip in brightness of Tabby’s star when it dimmed by up to 22 percent before it returned to normal state. However, the first major dip of this star was observed in March 2011, when the brightness was reduced by up to 15 percent. Another one was recorded in February 2013 and reduced the brightness of the star by up to 22 percent. Moreover, by analyzing old photographic plates, it was discovered that the star has gradually faded from 1890 to 1989 by about 20 percent.

Now, astronomers have found that KIC 8462852 once again showcases strange behavior. On May 19, it was noticed that the star began to dim one more time.

“We see it is complex in shape and lasts several days. This is similar to the previous dips. Hard to say any more because the dip is continuing to happen,” Boyajian told Astrowatch.net.

Baffled by the star’s weird behavior, the scientific community still argues what could be the real cause of the observed irregular dimmings. Some say it is due to an internal processes, while some suggest that it could be caused by a swarm of comets and debris orbiting the star. However, the hypothesis which created the most buzz is that the dimmings could be caused by an alien megastructure surrounding the star.

The new dip in brightness currently in progress could offer more clues into the real nature of Tabby’s star and its neighborhood, helping to choose which explanation is the most plausible. However, it is still too soon to draw final conclusions as a lot of data from recent observations is waiting to be analyzed.

Boyajian admitted that the hypothesis regarding a group of comets or disintegrated planet causing irregular light fluctuations has not been ruled out yet, while the presence of some artificial structure around the star is very unlikely.

The team now endorses citizen scientists to point out their telescopes at Tabby’s star. Hence, over next days, more observations of KIC 8462852 are planned to be conducted in order to uncover more insight into its mysterious nature.

“Fellow astronomers have been extremely responsive and supportive to our calls, and we are hitting it with all we got,” Boyajian said.

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