Picture of the Day · NASA
NGC 3660 and Burçin's Galaxy
2026-05-26
The upper galaxy might be more photogenic, but the lower galaxy is more unusual. The galaxy up top is NGC 3660, a spiral galaxy similar to our own Milky Way galaxy in that it has several bright blue spiral arms and a central bar of stars, dust, and gas. Captured by chance in the featured deep and colorful image, surprisingly, is SN 2026cff, a supernova found just to the right of the central bar. Farther in the distance is the bottom galaxy, known informally as Burçin’s galaxy, but formally cataloged as LEDA 1000714. The center of this galaxy appears to be an old elliptical galaxy, but it is strangely surrounded by not one but two rings of stars. What created Burçin's galaxy is a mystery and remains a continuing topic of research, but it likely involves the accretion of one or more smaller galaxies.
via NASA APOD
Key facts
- Discovered by
- Karl Theodor Robert Luther
- Discovery date
- 23 November 1867
- Pronunciation
- / ær ə ˈ θj uː s ə /
- Minor planet category
- Main belt
- Adjectives
- Arethusian, Arethusean / ˌ ær ə ˈ θj uː z i ə n /
- Observation arc
- 143.53 yr (52424 d)
- Aphelion
- 3.53176 AU (528.344 Gm )
- Perihelion
- 2.59737 AU (388.561 Gm)
- Semi major axis
- 3.06457 AU (458.453 Gm)
- Orbital period sidereal
- 5.36 yr (1959.5 d )
- Average orbital speed
- 16.91 km/s
- Mean anomaly
- 250.185 °
- Mean motion
Article
95 Arethusa is a large main-belt asteroid. It was discovered by German astronomer Robert Luther on 23 November 1867, and named after one of the various Arethusas in Greek mythology. Arethusa has been observed occulting a star three times: first on 2 February 1998, and twice in January 2003.
This object is orbiting the Sun with a period of 5.36 years and an eccentricity of 0.15. The cross-section diameter is around 136 km and it is spinning with a rotation period of 8.7 hours. The spectrum matches a C-type asteroid, indicating a dark surface with a primitive carbonaceous composition.