Tonight's Sky
Sun
Sun
Moon
Moon
Mercury
Mercury
Venus
Venus
Mars
Mars
Jupiter
Jupiter
Saturn
Saturn

Tonight's Sky — Change location

OR

Searching...

Tonight's Sky — Select location

Tonight's Sky — Enter coordinates

° '
° '

The rose-red glow of star formation

NGC 371 is home to an unexpectedly large number of variable stars.
NGC371
The vivid red cloud in this new image from ESO’s Very Large Telescope is a region of glowing hydrogen surrounding the star cluster NGC 371. This stellar nursery lies in our neighbouring galaxy, the Small Magellanic Cloud. ESO/Manu Mejias
The vivid red cloud in this new image from the European Southern Observatory’s (ESO) Very Large Telescope (VLT) is a region of glowing hydrogen surrounding the star cluster NGC 371. This stellar nursery lies in our neighboring galaxy, the Small Magellanic Cloud.

The object dominating this image may resemble a pool of spilled blood, but rather than being associated with death, such regions of ionized hydrogen — known as HII regions — are sites of creation with high rates of recent star birth. NGC 371 is an example of this — it is an open cluster surrounded by a nebula. The stars in open clusters all originate from the same diffuse HII region, and over time, the majority of the hydrogen is used up by star formation, leaving behind a shell of hydrogen such as the one in this image, along with a cluster of hot young stars.

The host galaxy to NGC 371, the Small Magellanic Cloud, is a dwarf galaxy 200,000 light-years away, which makes it one of the closest galaxies to the Milky Way. In addition, the Small Magellanic Cloud contains stars at all stages of their evolution — from the highly luminous young stars found in NGC 371 to supernova remnants of dead stars. These energetic youngsters emit copious amounts of ultraviolet radiation causing surrounding gas, such as leftover hydrogen from their parent nebula, to light up with a colorful glow that extends for hundreds of light-years in every direction. The phenomenon is depicted beautifully in this image, taken using the FORS1 instrument on ESO's (VLT).

Open clusters are by no means rare, and there are numerous fine examples in our own Milky Way. However, NGC 371 is of particular interest due to the unexpectedly large number of variable stars it contains. These are stars that change in brightness over time. A particularly interesting type of variable star, known as slowly pulsating B stars, can also be used to study the interior of stars through asteroseismology, and several of these have been confirmed in this cluster. Variable stars play a pivotal role in astronomy, and some types are invaluable for determining distances to far-off galaxies and the age of the universe.

0

JOIN THE DISCUSSION

Read and share your comments on this article
Comment on this article
Want to leave a comment?
Only registered members of Astronomy.com are allowed to comment on this article. Registration is FREE and only takes a couple minutes.

Login or Register now.
0 comments
ADVERTISEMENT

FREE EMAIL NEWSLETTER

Receive news, sky-event information, observing tips, and more from Astronomy's weekly email newsletter.

ADVERTISEMENT
ADVERTISEMENT
BoxProductcovernov

Click here to receive a FREE e-Guide exclusively from Astronomy magazine.

Find us on Facebook

Loading...