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
- K. Reinmuth
- Discovery site
- Heidelberg Obs.
- Discovery date
- 22 August 1919
- Named after
- Name picked from the almanac , Lahrer Hinkender Bote
- Alternative designations
- A919 QD · 1919 FR, A907 CA · 1907 CA, 1943 PB
- Minor planet category
- main-belt · ( outer ) , Itha
- Observation arc
- 99.72 yr (36,421 d)
- Aphelion
- 3.4078 AU
- Perihelion
- 2.3197 AU
- Semi major axis
- 2.8637 AU
- Orbital period sidereal
- 4.85 yr (1,770 d)
- Mean anomaly
- 273.51 °
- Mean motion
Wikidata facts
- Instance of
- asteroid
- Followed by
- Q158000
- Follows
- Q157993
- Parent body
- Sun
- Minor-planet group
- asteroid belt
- Diameter
- +21.561
- Orbital period
- +1772.437359618509
- Image
- 000918-asteroid shape model (918) Itha.png
Show 3 more facts
Article
918 Itha (prov. designation: A919 QD or 1919 FR) is a stony asteroid and the namesake as well as the principal body of the Itha family, located in the outer region of the asteroid belt. It was discovered by German astronomer Karl Reinmuth at the Heidelberg Observatory on 22 August 1919. The S-type asteroid has a notably short rotation period of only 3.5 hours and measures approximately 21 kilometers (13 miles) in diameter. It was named "Itha", a female name taken from the almanac Lahrer Hinkender Bote, unrelated to the discoverer's contemporaries.
Orbit and classification