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
- 18 March 1922
- Pronunciation
- / ə ˈ r eɪ l i ə /
- Named after
- Aralia , (genus of plants)
- Alternative designations
- A922 FB · 1954 SE, 1922 LR
- Minor planet category
- main-belt · ( outer ) , Ursula
- Observation arc
- 97.80 yr (35,720 d)
- Aphelion
- 3.5717 AU
- Perihelion
- 2.8522 AU
- Semi major axis
- 3.2119 AU
- Orbital period sidereal
- 5.76 yr (2,103 d)
- Mean anomaly
Article
973 Aralia (prov. designation: A922 FB or 1922 LR) is an asteroid of the Ursula family located in the outer regions of the asteroid belt, approximately 52 kilometers (32 miles) in diameter. It was discovered on 18 March 1922, by German astronomer Karl Reinmuth at the Heidelberg Observatory in southern Germany. The Xk-type asteroid has a rotation period of 7.3 hours. It was named after the genus of ivy-like plant Aralia, also known as "spikenard".
Orbit and classification