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
- 22 September 1859
- Pronunciation
- / n ɪ ˈ m ɒ s ɪ n iː /
- Named after
- Mnemosyne
- Minor planet category
- Main belt
- Adjectives
- Mnemosynean / ˌ n ɛ m ə s ɪ ˈ n iː ə n / , Mnemosynian / n ɛ m ə ˈ s ɪ n i ə n /
- Aphelion
- 526.785 Gm (3.521 AU )
- Perihelion
- 415.379 Gm (2.777 AU)
- Semi major axis
- 471.082 Gm (3.149 AU)
- Orbital period sidereal
- 2,041.056 d (5.59 a )
- Mean anomaly
- 68.001°
- Inclination
- 15.200°
- Longitude of ascending node
Wikidata facts
- Instance of
- asteroid
- Named after
- Mnemosyne
- Followed by
- 58 Concordia
- Follows
- 56 Melete
- Parent body
- Sun
- Minor-planet group
- asteroid belt
- Diameter
- +112.59
- Orbital period
- +2047.67357080451
Show 4 more facts
- P65
Article
57 Mnemosyne is a large main belt asteroid. It is a stony S-type asteroid in composition. This object was discovered by Robert Luther on 22 September 1859 in Düsseldorf. Its name was chosen by Martin Hoek, the director of the Utrecht Observatory, in reference to Mnemosyne, a Titaness in Greek mythology.
This asteroid is orbiting in the outer main belt at a distance of 3.149 AU from the Sun with an eccentricity (ovalness) of 0.118 and a period of 5.58811 a. The orbital plane is inclined at an angle of 15.2° to the ecliptic. The orbital period of this asteroid is close to a 2:1 commensurability with Jupiter, which made it useful for perturbation measurements to derive the mass of the planet.