Picture of the Day · NASA
PK 164 +31.1: The Headphone Nebula
2026-05-27
What is a pair of headphones doing in the sky? Today’s image features the Headphone Nebula, also known as PK 164 +31.1 or Jones-Emberson 1. This planetary nebula, the remnant of a dying Sun-like star, faintly occupies an angular region of the Lynx constellation about 1/5th the diameter of the full moon. The red and blue-ish green colors trace hydrogen and oxygen atoms, respectively, that have been excited and ionized by the nebula's central white dwarf. The headphone shape, where two lobes of hydrogen puncture the inner region of oxygen, adds this object to a long list of oddly shaped nebulae. The morphology of such strange nebulae hint at the presence of a stellar or planetary companion, which can stir the material flowing out from the dying star. You can listen to Hubble and JWST sonifications of planetary nebulae through your very own headphones!
via NASA APOD
Key facts
- Discovered by
- W. Baade
- Discovery site
- Bergedorf Obs.
- Discovery date
- 31 October 1920
- Pronunciation
- / h ɪ ˈ d æ l ɡ oʊ /
- Named after
- Miguel Hidalgo y Costilla , (Mexican revolutionary)
- Alternative designations
- 1920 HZ · A920 UB
- Minor planet category
- centaur · main-belt , unusual
- Symbol
- (astrological)
- Observation arc
- 97.97 yr (35,784 d)
- Aphelion
- 9.5345 AU
- Perihelion
- 1.9474 AU
- Semi major axis
- 5.7410 AU
- Orbital period sidereal
Wikidata facts
- Instance of
- asteroid
- Named after
- Miguel Hidalgo Y Costilla
- Followed by
- Q158171
- Follows
- 943 Begonia
- Parent body
- Sun
- Minor-planet group
- centaur
- Diameter
- +38.0
- Orbital period
- +5007.693155578201
- Image
- 944Hidalgo-position.png
Show 4 more facts
- P61
- Walter Baade
Article
944 Hidalgo /hɪˈdælɡoʊ/ is a centaur and unusual object on an eccentric, cometary-like orbit between the asteroid belt and the outer Solar System, approximately 52 kilometers (32 miles) in diameter. Discovered by German astronomer Walter Baade in 1920, it is the first member of the dynamical class of centaurs ever to be discovered. The dark D-type object has a rotation period of 10.1 hours and likely an elongated shape. It was named after Mexican revolutionary Miguel Hidalgo y Costilla.
Discovery and naming