Hippocampus
| Hippocampus | |
|---|---|
|
|
| Hippocamp (top right) and other inner Neptune moons and rings. | |
| Provisional or systematic name | S / 2004 N 1 |
| Central body | Neptune |
| Properties of the orbit | |
| Major semi-axis | 105,283 km |
| Periapsis | unknown |
| Apoapsis | unknown |
| Orbital time | 0.9362 d |
| Physical Properties | |
| Apparent brightness | 26.5 mag |
| Medium diameter | 16 to 20 km |
| Acceleration of gravity on the surface | ≈0 m / s 2 |
| Escape speed | ≈0 m / s |
| discovery | |
| Explorer | |
| Date of discovery | July, 1st 2013 |
Hippocamp (also S / 2004 N 1 and Neptune XIV ) is the sixth innermost and smallest known moon on the planet Neptune .
discovery
S / 2004 N 1 was discovered on July 1, 2013 by Mark Showalter at the SETI Institute in Mountain View / California while he was investigating Neptune's ring system. He noticed a white point between the orbits of the moons Larissa and Proteus . In more than 150 archive recordings of the Hubble Space Telescope between 2004 and 2009, the point appeared again and again, from which it was able to calculate the circular orbit of the moon. Due to its low brightness, it could not be seen on images taken by the Voyager 2 space probe , which flew past Neptune in 1989.
designation
It was named a hippocamp on February 20, 2019. A hippocamp (Greek ἱππόκαμπος, from ἵππος “horse” and κάμπος “sea monster”) is a mythical creature, with a horse in front and a fish in the back. The spelling Hippocamp goes back to the Latin form hippocampus. The seahorses also have the Latin generic name hippocampus .
Orbit data
Hippocamp orbits Neptune on an approximately circular, barely inclined orbit between the moons Larissa and Proteus at an average distance of 105,283 km from the center. The approximately 19 km large moon needs 22 hours 28.1 minutes for one orbit.
Structure and physical data
If the hippocamp has a small albedo like other nearby moons , its apparent magnitude of 26.5 mag results in a maximum diameter of 16–20 km. This would make it the smallest of the 14 known Neptune moons. Despite its low brightness, it can only just be seen in the images from the Hubble Space Telescope.
Web links
- MPC 111804: Numbering of Natural Satellites September 25, 2018 (numbering)
- Tim Kröplin: New Neptune Moon discovered. His name: Hippocamp , zeit.de, February 20, 2019.
- scinexx.de: Mystery of the "impossible" moon solved February 21, 2019
Individual evidence
- ↑ Hubble Finds New Neptune Moon Space Telescope Science Institute , July 15, 2013, accessed July 16, 2013.
- ↑ a b c Kelly Beatty: Neptune's Newest Moon Sky & Telescope , July 15, 2013, accessed June 30, 2017.
- ↑ Minor Planet Electronic Circular 2019-D16
- ↑ Sven Stockrahm: Astronomers encounter new Neptune moon in the archive. In: zeit.de . July 16, 2013, accessed February 22, 2019 .