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 , I. Groeneveld
- Discovery site
- Heidelberg Obs.
- Discovery date
- 9 September 1956
- Named after
- Jan Oort (astronomer)
- Alternative designations
- 1956 RB · 1945 TD, 1947 DA · 1950 PZ, 1950 RU · 1951 XW, 1955 MW · 1956 SD, 1964 DA · A917 TD
- Minor planet category
- main-belt · Themis
- Observation arc
- 71.42 yr (26,086 days)
- Aphelion
- 3.7153 AU
- Perihelion
- 2.6084 AU
- Semi major axis
- 3.1618 AU
- Orbital period sidereal
- 5.62 yr (2,054 days)
- Mean anomaly
- 240.25 °
- Inclination
Wikidata facts
- Instance of
- asteroid
- Named after
- Jan Hendrik Oort
- Followed by
- 1692 Subbotina
- Follows
- Q142409
- Parent body
- Sun
- Minor-planet group
- asteroid belt
- Diameter
- +33.644
- Orbital period
- +2055.228571722609
- Image
- 1691Oort (Lightcurve Inversion).png
Show 4 more facts
Article
1691 Oort, provisional designation 1956 RB, is a rare-type carbonaceous Themistian asteroid from the outer region of the asteroid belt, approximately 33 kilometers in diameter.
It was discovered on 9 September 1956, by German astronomer Karl Reinmuth and Dutch astronomer Ingrid van Houten-Groeneveld at Heidelberg Observatory in south-west Germany. It was later named after Dutch astronomer Jan Oort.