Image credit & copyright: European Southern Observatory (ESO)/Very Large Telescope (VLT).
In this post we’re going to detail the beautiful Triangulum galaxy which gets its name from being the prominent galaxy in the constellation Triangulum. In this image, captured by the European Southern Observatory’s (ESO), Very Large Telescope (VLT) in the Atacama Desert of Chile, we can see this galaxy in brilliant detail. It’s inclined at 55 degrees to our line of sight which shows off the beautiful H II star forming regions throughout its spiral arms, while above and below the plane of the galaxy, more than 50 globular star clusters (likely much more than that) occupy the halo.
M33 contains some awesome features as well, such as the largest stellar mass black hole currently known which goes by the name M33 X-7. This 16 solar mass black hole orbits its partner star every 3.5 days.
If you look to roughly the 7 o’clock position you can see a large pink and white region known as New General Catalog 604 (NGC 604) and it’s the largest H II star forming region that we know of in the local group. Perhaps I’ll create a post on that next.
M33’s nucleus has a black hole of upwards of 2,000 solar masses so it doesn’t appear to have a supermassive black hole but what it does have is the brightest steady X-ray source in the local group.
With a diameter of roughly 60,000 light years and containing roughly 45 billion stars, M33 is much smaller than our Milky Way but it still ranks third in size as far as our local group of galaxies goes, after us and the great Andromeda (M31).
At a distance of 3 million light years and with an apparent magnitude of about 5.7, M33 is one of the most distant constant deep sky objects that you can see with the unaided eye. That’s assuming you’re in very dark conditions.
M33 is also thought to be gravitationally associated with M31 Andromeda as it has been discovered that the two share filaments of stars and material that stretch from one galaxy to the other due to a possible interaction billions of years ago. Fast forward a few billion years and it seems that M33 wants in on the Milky Way and Andromeda collision. What that means exactly nobody knows. M33 might make this train wreck a three way collision or it may be absorbed by Andromeda before it collides with the Milky Way in 4 billion years. Some say it will survive the collision and orbit the mass that was Andromeda and the Milky Way before finally being absorbed. Either way, when these galaxies finally come together it’s estimated that there’s so much space between the stars that none of the trillion plus stars will actually collide with one another.
NAME: Messier 33 (M33), NGC 598, Triangulum Galaxy.
WHAT IS IT?: Spiral galaxy.
HOW FAR AWAY IS IT?: 3 million light years.
HOW BIG IS IT?: Roughly 60,000 light years in diameter.
APPARENT MAGNITUDE: Naked eye visible 5.7.
WHERE IS IT? (General): Northern constellation, Triangulum.
WHERE IS IT? (Exact RA/Dec J2000): RA 01h 33m 50.02s / Dec +30° 39′ 36.7″.
ESO page for this image: https://www.eso.org/public/usa/images/eso1424a/