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
- Elia Millosevich
- Discovery date
- 1 March 1891
- Pronunciation
- / ˈ j uː n ɪ t æ s /
- Alternative designations
- A891 EA
- Minor planet category
- Main belt
- Observation arc
- 124.78 yr (45575 d)
- Aphelion
- 2.71480 AU (406.128 Gm )
- Perihelion
- 2.0009 AU (299.33 Gm)
- Semi major axis
- 2.35785 AU (352.729 Gm)
- Orbital period sidereal
- 3.62 yr (1322.4 d )
- Mean anomaly
- 88.9729 °
- Mean motion
- 0° 16 20.014 / day
- Inclination
- 7.2779°
Wikidata facts
- Instance of
- asteroid
- Named after
- Angelo Secchi
- Followed by
- Q150797
- Follows
- Q150730
- Parent body
- Sun
- Minor-planet group
- asteroid belt
- Diameter
- +47.2
- Orbital period
- +1322.108608816069
- Image
- 306Unitas (Lightcurve Inversion).png
Show 3 more facts
Article
306 Unitas is a typical main belt asteroid that was discovered by Elia Millosevich on 1 March 1891 in Rome. The asteroid was named by the director of the Modena Observatory in honor of the Italian astronomer Angelo Secchi (author of Unità delle forze fisiche) and the unification of Italy.
This object is orbiting the Sun with a distance of 2.36 AU and an eccentricity of 0.15 with an orbital period of 3.62 years. Its orbital plane is inclined at an angle of 7.28° to the plane of the ecliptic. Although 306 Unitas has an orbit similar to the Vesta family asteroids, it was found to be an unrelated interloper on the basis of its non-matching spectral type. Based on infrared measurements, it has a diameter of 47.2 km. It is classified as a stony S-type asteroid.