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
- R. Luther
- Discovery date
- October 5, 1855
- Designation
- (37) Fides
- Pronunciation
- / ˈ f aɪ d iː z /
- Named after
- Fides
- Alternative names
- 1925 WH
- Minor planet category
- Main belt
- Adjectives
- Fidean / ˈ f ɪ d i ə n /
- Symbol
- (historical)
- Observation arc
- 167 yr
- Aphelion
- 464.902 million km (3.108 AU )
- Perihelion
- 325.937 million km (2.179 AU)
- Semi major axis
- 395.419 million km (2.643 AU)
Wikidata facts
- Instance of
- asteroid
- Named after
- Fides
- Followed by
- 38 Leda
- Follows
- 36 Atalante
- Parent body
- Sun
- Minor-planet group
- asteroid belt
- Diameter
- +108.35
- Mass
- +1.3
- Orbital period
- +1569.472209666668
- Image
- 37Fides (Lightcurve Inversion).png
Show 4 more facts
Article
37 Fides (/ˈfaɪdiːz/) is a large main-belt asteroid. It was discovered by German astronomer Karl Theodor Robert Luther on October 5, 1855, and named after Fides, the Roman goddess of loyalty. Fides was the last of the main-belt asteroids to be assigned an iconic symbol, a Latin cross U+271D ✝ (). 37 Fides is also a S-type asteroid in the Tholen classification system.
Photometric observations of this asteroid at multiple observatories during 1981–82 gave an unusual light curve with three minima and maxima. The curve changed with varying phase angle of the asteroid relative to the viewer and the position of the Sun, indicating the changing influence of shadows cast by surface features. The composite light curve has a best fit period estimate of 7.33 hours. Austrian astronomer Hans Josef Schober has suggested that the multiple minima and maxima during each period may be an indication of a binary nature.