A team of astronomers announces that they have isolated several clues indicating the possible presence of a giant planet orbiting Vega, one of the brightest stars in the night sky. These results, which remain to be confirmed, are published in The astrophysical journal.
Vega is the brightest star in the constellation Lyra. Relatively young compared to our star, but also twice as massive, it is around 25 light years of the earth. So far, we haven’t discovered any planet orbiting this iconic star. However, that could be about to change.
Vega is a type A star. Objects that fit into this category tend to be bigger, younger, and spin much faster than the sun. Vega turns for example around its axis once every sixteen hours, while our star completes a rotation on itself in twenty-seven earth days.
With such a rate, it is then difficult for researchers to collect precise data on the movement of the star and, by extension, on the possible planets in orbit. However, we can always try. As part of a recent study, astronomer Spencer Hurt and his team at the University of Colorado covered a decade of data collected by the Fred Lawrence Whipple Observatory in Arizona.
For this work, the researchers focused on the “radial velocity” method, noticing slight oscillations in the Vega star’s motion which is usually caused by the gravitational pulling of an orbiting world. “If you have a planet around a star, it can swing it back and forth.“, Explains Samuel Quinn, who co-signs this work.
A giant and (very) hot world
As a result, the researchers isolated a signal indicating that Vega could host one of these worlds. According to the study, it could be a “hot Neptune” or perhaps a “hot Jupiter” moving so close to Vega that it would circle it in less than two and a half days. For comparison, Mercury, which is the closest planet to the Sun, circles it every 88 days.
If this is indeed the case, this candidate planet could have average surface temperatures of nearly 3000 ° C, thus classifying itself as the second hottest world known to the science behind KELT-9b (visible above). However, additional work will be necessary to confirm its presence.