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
- Johann Palisa
- Discovery date
- 6 April 1891
- Pronunciation
- / f r ə ˈ t ɜːr n ɪ t æ s /
- Named after
- fraternity
- Minor planet category
- Main belt
- Observation arc
- 125.03 yr (45667 d)
- Aphelion
- 2.97127 AU (444.496 Gm )
- Perihelion
- 2.35779 AU (352.720 Gm)
- Semi major axis
- 2.66453 AU (398.608 Gm)
- Orbital period sidereal
- 4.35 yr (1,588.7 d) 4.35 yr (1588.7 d )
- Mean anomaly
- 190.308 °
- Mean motion
- 0° 13 35.785 / day
- Inclination
Wikidata facts
- Instance of
- asteroid
- Named after
- fraternal organization
- Followed by
- 310 Margarita
- Follows
- 308 Polyxo
- Parent body
- Sun
- Minor-planet group
- asteroid belt
- Diameter
- +41.075
- Orbital period
- +1587.497665671046
Show 3 more facts
- P65
Article
309 Fraternitas is a typical Main belt asteroid. It was discovered by Johann Palisa on 6 April 1891 in Vienna. The asteroid name is Latin for 'fraternity'; it was so named in order to commemorate the 25th anniversary of the Maturitätsprüfung Fraternity.
This minor planet is orbiting the Sun at a distance of 2.665 AU with an orbital eccentricity (ovalness) of 0.115 and a period of 4.35 yr. The orbital plane is inclined at an angle of 3.72° of the ecliptic. Analysis of the asymmetric bimodal light curve of the asteroid from photometric data collected during 2014 provide a rotation period of 22.398±0.001 h with a brightness variation of 0.12±0.01 in magnitude.