Astronomers using NASA’s Hubble Space Telescope have discovered five planetary disks around young stars.
This image shows a debris disk around HD 141943. Image credit: NASA / ESA / R. Soummer, Ann Feild, STScI.
According to their paper published in the Astrophysical Journal (arXiv.org version), three disks – around stars HD 30447, HD 35841, and HD 141943 – appear edge-on, while the other two – around HD 191089 and HD 202917 – appear inclined.
“One star that is particularly interesting is HD 141943. It is an exact twin of our Sun during the epoch of terrestrial planet formation in our own Solar System,” said study co-author Dr Christine Chen from the Space Telescope Science Institute in Baltimore.
HD 141943 exhibits an asymmetrical, edge-on disk. This asymmetry could be evidence the disk is being gravitationally sculpted by the tug of one or more unseen planets.
Previous studies suggested that dusty disks could exist around HD 30447, HD 35841, HD 141943, HD 191089 and HD 202917. Small dust particles in the disks might scatter light and therefore make the disks visible. But when Hubble first viewed the stars in 1999-2006, no disks were detected.
This is an artist’s impression of a debris disk around HD 141943. Image credit: NASA / ESA / R. Soummer, Ann Feild, STScI.
Thanks to new image processing techniques, Dr Chen with colleagues reanalyzed the archived Hubble images. This time, they could unequivocally see the debris disks and even determine their shapes.
“These findings increase the number of debris disks seen in scattered light from 18 to 23,” said study lead author Dr Rémi Soummer, also from the Space Telescope Science Institute.
“By significantly adding to the known population and by showing the variety of shapes in these new disks, Hubble can help astronomers learn more about how planetary systems form and evolve.”
Dr Marshall Perrin, an astronomer with the Space Telescope Science Institute and a co-author of the study, added: “being able to see these disks now also has let us plan further observations to study them in even more detail using other Hubble instruments and large telescopes on the ground.”
______
Rémi Soummer et al. 2014. Five Debris Disks Newly Revealed in Scattered Light from the Hubble Space Telescope NICMOS Archive. ApJ 786, L23; doi: 10.1088/2041-8205/786/2/L23
