NGC 2438

NGC 2438
Observation data (Epoch J2000.0)
Right ascension	07h 41.8m
Declination	-14° 44′
Distance	2,900 ly
Apparent magnitude (V)	+10.8
Apparent dimensions (V)	1.1 arcmins
Constellation	Puppis
Physical characteristics
Radius	-
Absolute magnitude (V)	-
Notable features	Superimposed on Messier 46
Other designations	H IV.39, FC 87, PK 231+4.2
See also: Planetary nebula, Lists of nebulae

NGC 2438 is a planetary nebula about 3,000 light years away in the constellation Puppis.^[1] It was discovered by William Herschel on March 19, 1786.^[2] The planetary nebula NGC 2438 appears to lie within the cluster M46, but it is most likely unrelated since it does not share the cluster's radial velocity.^[3][4] The case is yet another example of a superposed pair, joining the famed case of NGC 2818.^[5][3]

Long exposures have shown that this planetary nebula has an extended halo,^[6] while the more easily visible portion probably dates to the death of the red giant in its center.^[2]

Central star

The central star of this planetary nebula is a 17.7-magnitude white dwarf,^[2] with surface temperature of about 75,000 K (74,700 °C).^[7] It's one of the hottest stars known.

References

1. ^ "Astronomy Picture of the Day, Planetary Nebula NGC 2438". NASA. 2011-04-07. http://apod.nasa.gov/apod/ap110407.html. Retrieved 2011-04-08. 
2. ^ ^{a b c} "NGC Objects: NGC 2400 - 2449". http://cseligman.com/text/atlas/ngc24.htm#2438. Retrieved 2011-04-08. 
3. ^ ^{a b} Majaess D. J., Turner D., Lane D. (2007). In Search of Possible Associations between Planetary Nebulae and Open Clusters, PASP, 119, 1349
4. ^ Kiss, L. L., Szabó, Gy. M., Balog, Z., Parker, Q. A., Frew, D. J. (2008). AAOmega radial velocities rule out current membership of the planetary nebula NGC 2438 in the open cluster M46, MNRAS
5. ^ Mermilliod, J.-C., Clariá, J. J., Andersen, J., Piatti, A. E., Mayor, M. (2001). Red giants in open clusters. IX. NGC 2324, 2818, 3960 and 6259, A&A
6. ^ "NGC 2438". SEDS. http://seds.org/messier/xtra/ngc/n2438.html. Retrieved 2011-04-08. 
7. ^ "Planetary Nebula NGC 2438 in Puppis". http://www.kopernik.org/images/archive/n2438.htm. Retrieved 2011-04-08. 

See also

• List of planetary nebulae
• List of NGC objects

External links

• NGC 2438 @ SEDS NGC objects pages

Coordinates: 07^h 41^m 50.6^s, −14° 44′ 05″