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
- A. Schwassmann
- Discovery site
- Bergedorf Obs.
- Discovery date
- 18 November 1922
- Pronunciation
- / ʃ w æ s ˈ m æ n i ə , ʃ v ɑː s -/
- Named after
- Friedrich Karl Arnold Schwassmann , (discoverer himself)
- Alternative designations
- A922 WD · 1922 MW, 1935 UE · 1935 UF
- Minor planet category
- main-belt · ( middle ) , background
- Observation arc
- 96.49 yr (35,244 d)
- Aphelion
- 3.3261 AU
- Perihelion
- 1.9915 AU
- Semi major axis
- 2.6588 AU
- Orbital period sidereal
- 4.34 yr (1,584 d)
- Mean anomaly
Wikidata facts
- Instance of
- asteroid
- Named after
- Friedrich Karl Arnold Schwassmann
- Followed by
- 990 Yerkes
- Follows
- Q158484
- Parent body
- Sun
- Minor-planet group
- asteroid belt
- Diameter
- +12.63
- Orbital period
- +1586.027121299011
Show 3 more facts
Article
989 Schwassmannia (prov. designation: A922 WD or 1922 MW) is a stony background asteroid and a slow rotator from the central regions of the asteroid belt, approximately 12.5 kilometers (7.8 miles) in diameter. It was discovered on 18 November 1922, by astronomer Friedrich Karl Arnold Schwassmann at the Bergedorf Observatory in Hamburg, Germany. The bright S/T-type asteroid has a long rotation period of 107.9 hours. It was named after the discoverer himself.
Orbit and classification