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
- James Craig Watson
- Discovery date
- 10 October 1868
- Pronunciation
- / d aɪ ˈ oʊ n iː /
- Named after
- Dione
- Alternative designations
- A868 TA, 1902 TA
- Minor planet category
- Main belt
- Observation arc
- 145.03 yr (52972 d)
- Aphelion
- 3.7032 AU (553.99 Gm )
- Perihelion
- 2.64584 AU (395.812 Gm)
- Semi major axis
- 3.17451 AU (474.900 Gm)
- Orbital period sidereal
- 5.66 yr (2065.9 d )
- Average orbital speed
- 16.61 km/s
- Mean anomaly
Wikidata facts
- Instance of
- asteroid
- Named after
- Dione
- Followed by
- 107 Camilla
- Follows
- 105 Artemis
- Parent body
- Sun
- Minor-planet group
- asteroid belt
- Diameter
- +207.869
- Orbital period
- +2073.71564096394
Show 5 more facts
- P65
Article
106 Dione is a large main-belt asteroid. It probably has a composition similar to 1 Ceres. It was discovered by J. C. Watson on October 10, 1868, and named after Dione, a Titaness in Greek mythology who was sometimes said to have been the mother of Aphrodite, the Greek goddess of love and beauty. It is listed as a member of the Hecuba group of asteroids that orbit near the 2:1 mean-motion resonance with Jupiter. The orbital period for this object is 5.66 years and it has an eccentricity of 0.17.
Measurements made with the IRAS observatory give a diameter of 169.92±7.86 km and a geometric albedo of 0.07±0.01. By comparison, the MIPS photometer on the Spitzer Space Telescope gives a diameter of 168.72±8.89 km and a geometric albedo of 0.07±0.01. Dione was observed to occult a dim star on January 19, 1983, by observers in Denmark, Germany and the Netherlands. A diameter of 147±3 km was deduced, closely matching the value acquired by the IRAS satellite. As of 2012, the mean diameter derived through occultation measurements is 176.7±0.4 km.