A TADPOLE IN THE DRAGON

At 420 million light years from Earth, in the constellation of the Dragon, there is this peculiar galaxy known both as Arp 188 and as Girino Galaxy, because of its shape that resembles that of the animal.

Arp 188 was formerly a normal spiral galaxy, whose structure was heavily deformed as a result of a frontal collision with a smaller intruder galaxy. The reciprocal gravitational interactions have ripped away material from both galaxies, which is then arranged to form the tidal tail visible in the image, which extends in space for 280 thousand light years.

The interactions then had as an additional effect to trigger numerous phenomena of star formation, as evidenced by the blue star clusters visible throughout the length of the tail.

If you look closely at the picture, you can also see in the upper right the intruder galaxy, partially hidden by the spiral arms of Arp 188. The two galaxies are in fact distinguished by their colors: Arp 188 appears a diffuse white, while the other is a bright blue.

Credit: NASA, ESA, Hubble, Amal Biju.