Canis Major dwarf facts for kids
Quick facts for kids Canis Major dwarf |
|
|---|---|
| Observation data (J2000 epoch) | |
| Constellation | Canis Major |
| Right ascension | 07h 12m 35.0s |
| Declination | -27° 40′ 00″ |
| Distance | 25,000 ly |
| Type | Irr |
| Apparent dimensions (V) | 12 degrees × 12 degrees |
| Notable features | - |
| Other designations | |
| CMa Dwarf, PGC 5065047 | |
| See also: Galaxy, List of galaxies | |
The Canis Major dwarf galaxy (also called the CMa dwarf or Canis Major overdensity) is a small group of stars. Some scientists think it might be a separate galaxy that is very close to our own Milky Way galaxy. You can find it in the same part of the sky as the constellation called Canis Major, which means "Greater Dog".
This tiny galaxy is thought to have about a billion stars! Many of these stars are red giants, which are very big and bright stars. The Canis Major dwarf is classified as an irregular galaxy, meaning it doesn't have a clear shape like a spiral or an oval.
Scientists believe it is the closest neighboring galaxy to our position in the Milky Way. It is about 25,000 light-years away from our Solar System. It is also about 52,000 light-years from the center of the Milky Way. This dwarf galaxy has a somewhat oval shape. It might have as many stars as the Sagittarius dwarf elliptical galaxy, which was previously thought to be the closest galaxy to us.
Is it a Real Galaxy?
The Canis Major dwarf was first found in 2003. However, some studies have raised questions about whether it is truly a separate galaxy.
What Scientists Found
In 2009, scientists looked closely at the area where the Canis Major dwarf is located. They found only ten RR Lyrae variable stars there. These are special stars that change how bright they are over time.
This small number of RR Lyrae stars is what we would expect to see in the outer parts of the Milky Way. It is not what we would expect from a completely separate dwarf galaxy. This means that the stars in the Canis Major "overdensity" might actually be part of our own Milky Way's outer layers, rather than a distinct galaxy on its own.
