From the treasure trove of images captured by NASA’s Hubble Space
Telescope, the space agency released an image Friday that shows a
distant galaxy as it begins it transit behind a star that lies much
closer to Earth. The transit is of significance because it allows
scientists to study the star HD 107146, which is very similar to the
sun.HD 107146 is about 90 light-years away from Earth, and its physical
properties are very similar to the sun. It has a mass of about 1.09
suns, and its size is about 99 percent that of the sun. But compared to
the 4.6 billion years the sun has been around, this star is a youngster
whose age is between 80 and 200 million years only. It also has a
circumstellar disk of orbiting debris that appears as the numerous
jagged spikes in the Hubble image. Given the star’s similarities to the
sun, this disk — visible to us face-on — could be similar to the
asteroids and the Kuiper belt in our solar system.
The “Vermin Galaxy” — which NASA said was a nickname coined by some
astronomers to display their annoyance at its presence — is much
farther away in space, compared to HD 107146. The pairing of the star
and the galaxy was first observed by Hubble in 2004, and then again in
2011, and the latter image is the one NASA released Friday. A 2009
paper, published in the Astrophysical Journal Letters, suggested the
presence of a planet at an orbital distance of 45-75 times the distance between Earth and the sun.