NGC 4565

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NGC 4565
Needle Galaxy 4565.jpeg
NGC 4565 or Needle Galaxy
Observation data (J2000 epoch)
Constellation Coma Berenices
Right ascension 12h 36m 20.8s[1]
Declination +25° 59′ 16″[1]
Redshift 0.004103[1]
Helio radial velocity 1230 ± 5 km/s[1]
Distance 42.7 ± 12 Mly (13.1 ± 3.7 Mpc)[2]
53 ± 4 Mly (16.2 ± 1.3 Mpc)[3]
Apparent magnitude (V) 10.42[1]
Characteristics
Type SA(s)b?[1]
Apparent size (V) 15′.90 × 1′.85[1]
Other designations
UGC 7772,[1] PGC 42038,[1] Caldwell 38
See also: Galaxy, List of galaxies

NGC 4565 (also known as the Needle Galaxy or Caldwell 38) is an edge-on spiral galaxy about 30 to 50 million light-years away in the constellation Coma Berenices.[2] It lies close to the North Galactic Pole and has a visual magnitude of approximately 10. It is known as the Needle Galaxy for its narrow profile.[4] First recorded in 1785 by William Herschel, it is a prominent example of an edge-on spiral galaxy.[5]

Characteristics[edit]

NGC 4565 is a giant spiral galaxy more luminous than the Andromeda Galaxy.[6] Much speculation exists in the literature as to the nature of the central bulge. In the absence of clear-cut dynamical data on the motions of stars in the bulge, the photometric data alone cannot adjudge among various options put forth. However, its exponential shape suggested that it is a barred spiral galaxy.[7] Studies with the help of the Spitzer Space Telescope not only confirmed the presence of a central bar but also showed a pseudobulge within it as well as an inner ring.[8][8]

NGC 4565 has at least two satellite galaxies, one of which is interacting with it.[9] It has a population of roughly 240 globular clusters, more than the Milky Way.[6]

NGC 4565 and apparently smaller NGC 4562, seen by the 24-inch telescope on Mt. Lemmon, USA.
A detailed view of part of the disc of the spiral galaxy NGC 4565 imaged by the Hubble Space Telescope.

References[edit]

  1. ^ a b c d e f g h i "Results for NGC 4565". NASA/IPAC Extragalactic Database. Retrieved 2006-10-12. 
  2. ^ a b "Distance Results for NGC 4565". NASA/IPAC Extragalactic Database. Retrieved 2010-05-02. 
  3. ^ Jensen, Joseph B.; Tonry, John L.; Barris, Brian J.; Thompson, Rodger I.; et al. (February 2003). "Measuring Distances and Probing the Unresolved Stellar Populations of Galaxies Using Infrared Surface Brightness Fluctuations". Astrophysical Journal. 583 (2): 712–726. arXiv:astro-ph/0210129Freely accessible. Bibcode:2003ApJ...583..712J. doi:10.1086/345430. 
  4. ^ NGC4565 at http://apod.nasa.gov/apod/ap040409.html
  5. ^ Spiral Galaxy NGC 4565 at http://www.eso.org/public/images/eso0525a/
  6. ^ a b Globular Cluster Systems in Galaxies Beyond the Local Group
  7. ^ "Intermediate-band surface photometry of the edge-on galaxy NGC 4565" at http://www.iop.org/EJ/article/1538-3881/123/3/1364/201272.text.html
  8. ^ a b Detection of a Distinct Pseudobulge Hidden Inside the ``Box-Shaped Bulge of NGC 4565
  9. ^ HALOGAS: H I Observations and Modeling of the Nearby Edge-on Spiral Galaxy NGC 4565

External links[edit]

Coordinates: Sky map 12h 36m 20.8s, +25° 59′ 16″