Chandra X-ray & NOAO Optical Composite of NGC 40 (2005-n40-more-1)

NGC 40 · planetary nebula

Bow-Tie Nebula

NGC 40 is a planetary nebula discovered by William Herschel on November 25, 1788, and is composed of hot gas around a dying star.

RA00h 13m 01sDec+72° 31' 18"

Image: (Credit: X-ray: NASA/CXC/RIT/J.Kastner & R.Montez.; Optical: NSF/AURA/NOAO/WIYN). Public domain, via Wikimedia Commons.

Identity & coordinates

Identification

Primary designation: NGC 40
All designations: NGC 40 · Bow-Tie Nebula
Object type: Planetary Nebula
Constellation: Cepheus
Best viewing: Autumn · Winter

Coordinates & physical

Right ascension (J2000): 00h 13m 01s
Declination (J2000): +72° 31' 18"
Apparent magnitude (V): —
Distance: —

III

Visibility tonight

The science

NGC 40 is a planetary nebula discovered by William Herschel on November 25, 1788, and is composed of hot gas around a dying star. The star has ejected its outer layer which has left behind a small, hot star. Radiation from the star causes the shed outer layer to heat to about 10,000 degrees Celsius and become visible as a planetary nebula. The nebula is about one light-year across. About 30,000 years from now, scientists theorize that NGC 40 will fade away, leaving only a white dwarf star approximately the size of Earth.

Summary adapted from Wikipedia · CC-BY-SA-4.0