Black Eye Galaxy
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| Galaxy | List of galaxies |
|---|---|
The Black Eye Galaxy (M64) |
|
| Observation data (Epoch J2000) |
|
| Constellation | Coma Berenices |
| Right ascension | 12h 56m 43.7s[1] |
| Declination | +21° 40′ 58″[1] |
| Redshift | 408 ± 4 km/s[1] |
| Distance | 24 ± 2 Mly (7.4 ± 0.6 Mpc)[2] |
| Type | (R)SA(rs)ab[1] |
| Apparent dimensions (V) | 10′.0 × 5′.4[1] |
| Apparent magnitude (V) | 9.4[1] |
| Notable features | |
| Other designations | |
|
Evil Eye Galaxy,[3] Sleeping Beauty Galaxy[citation needed] |
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The Black Eye Galaxy (aka Messier 64, M64, or NGC 4826) was discovered by Edward Pigott in March 1779, and independently by Johann Elert Bode in April of the same year, as well as by Charles Messier in 1780.
M64 is well known among amateur astronomers because of its appearance in small telescopes. It is a pinwheel-shaped spiral galaxy in the Coma Berenices constellation (Berenice's Hair).
The Black Eye Galaxy is about 24 million light-years (7.4 Mpc) from Earth. It has a spectacular dark band of absorbing dust in front of the galaxy's bright nucleus, giving rise to its nicknames of the "Black Eye" or "Evil Eye" galaxy.
Contents |
[edit] General information
At first glance, M64 seems to be a fairly normal pinwheel-shaped spiral galaxy. As in the majority of galaxies, all of the stars in M64 are rotating in the same direction, clockwise as seen in the Hubble image.
However, recent detailed studies have led to the remarkable discovery that the interstellar gas in the outer regions of M64 rotates in the opposite direction from the gas and stars in the inner regions. The inner region has a radius of only approximately 3,000 light-years, while the outer section extends another 40,000 light-years. This pattern is believed to trigger the creation of many new stars around the boundary separating the 2 regions.
A collision of two galaxies has left a merged star system with an unusual appearance as well as bizarre internal motions. Astronomers believe that the oppositely rotating gas arose when M64 absorbed a satellite galaxy that collided with it, perhaps more than one billion years ago. Active formation of new stars is occurring in the shear region where the oppositely rotating gases collide, are compressed, and contract.
Particularly noticeable in the image are hot, blue young stars that have just formed, along with pink clouds of glowing hydrogen gas that fluoresce when exposed to ultraviolet light from newly formed stars.
The small galaxy that impinged on its neighbour has now been almost completely destroyed, its stars either merged with the main galaxy or scattered into space, but signs of the collision persist in the backward motion of gas at the outer edge of M64.
[edit] Image Notes
- Extended caption for image in Infobox
Messier Object 64, the Black Eye Galaxy. Particularly noticeable in this image are hot, blue, rather old stars, along with pink clouds of glowing hydrogen gas that fluoresce when exposed to ultraviolet light from newly formed stars.
[edit] External links
- Messier 64, SEDS Messier pages
- Hubblesite description and high resolution images
- WIKISKY.ORG, SDSS image, M64
[edit] References
- ^ a b c d e f g h i j NASA/IPAC Extragalactic Database. Results for NGC 4826. Retrieved on 2006-11-06.
- ^ J. L. Tonry, A. Dressler, J. P. Blakeslee, E. A. Ajhar, A. B. Fletcher, G. A. Luppino, M. R. Metzger, C. B. Moore (2001). "The SBF Survey of Galaxy Distances. IV. SBF Magnitudes, Colors, and Distances". Astrophysical Journal 546 (2): 681-693.
- ^ SIMBAD Astronomical Database. Results for NGC 4826. Retrieved on 2006-11-06.
