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
- Auguste Charlois
- Discovery date
- 19 December 1894
- Pronunciation
- / v i ˈ ɛ n ə /
- Named after
- Vienna
- Alternative designations
- 1894 BM
- Minor planet category
- Main belt
- Observation arc
- 117.45 yr (42,900 d)
- Aphelion
- 3.28657 AU (491.664 Gm )
- Perihelion
- 1.98686 AU (297.230 Gm)
- Semi major axis
- 2.63671 AU (394.446 Gm)
- Orbital period sidereal
- 4.28 yr (1,563.8 d)
- Mean anomaly
- 202.358 °
- Mean motion
- 0° 13 48.731 / day
Article
397 Vienna is a typical Main belt asteroid. It was discovered by French astronomer Auguste Charlois on 19 December 1894 in Nice. It was most likely named after the city of Vienna, Austria. This object is orbiting the Sun at a distance of 2.64 AU with an orbital eccentricity (ovalness) of 0.246 and a period of 4.28 yr. The orbital plane is inclined at an angle of 12.85° to the ecliptic.
Photometric observations from multiple sites during 2017 were combined to produce an irregular light curve showing a rotation period of 15.461±0.001 h with a luminosity amplitude of 0.16±0.02 in magnitude. This result is consistent with previous measurements. The Tholen spectral type of this object is S and the SMASSII spectral type is K. Although the 'S' class suggests a stony composition, the latter class is consistent with carbonaceous chondrite meteorites. Infrared observations from NEOWISE indicate a diameter of 49 km.