Belinda (moon)
| Belinda | |
|---|---|
 |
|
| Belinda, recorded by Voyager 2 | |
| Provisional or systematic name | S / 1986 U 5 |
| Central body | Uranus |
| Properties of the orbit | |
| Major semi-axis | 75,255.613 ± 0.057 km |
| Periapsis | 75,250.345 km |
| Apoapsis | 75,260.881 km |
| eccentricity | 0.00007 ± 0.000073 |
| Orbit inclination | 0.03063 ± 0.028 (equatorial plane) ° |
| Orbital time | 0.623527470 ± 0.000000017 d |
| Mean orbital velocity | 8.7771 km / s |
| Physical Properties | |
| Albedo | 0.08 ± 0.01 |
| Apparent brightness | 21.47 ± 0.09 mag |
| Medium diameter | 80.6 ± 16 (128 × 64 × 64) km |
| Dimensions | 356,683,087,077,132,000 kg |
| surface | 20,408.92 km 2 |
| Medium density | ≈ 1.3 g / cm 3 |
| Acceleration of gravity on the surface | ≈ 0.0149 m / s 2 |
| Escape speed | ≈ 34.52 m / s |
| Surface temperature | ≈ −184 to −209 ° C / 64–89 K |
| discovery | |
| Explorer |
Voyager 2 |
| Date of discovery | January 13, 1986 |
| Remarks | Physical data relatively imprecise. |
Belinda (also Uranus XIV ) is the tenth innermost and one of the medium-sized of the 27 known moons of the planet Uranus .
Discovery and naming
Belinda was discovered on January 13, 1986 by the astronomer Stephen P. Synnott (Voyager Science Team) together with Desdemona and Rosalind on photographs taken by the Voyager 2 space probe . The discovery was announced on January 16, 1986 by the International Astronomical Union (IAU); the moon was initially given the provisional designation S / 1986 U 5 .
Belinda is the main female character from Alexander Pope's verse epic The Robbery . The poem has a parodic touch and Belinda is based on the contemporaries Arabella Fermor (1696-1737) and her admirer Lord Robert Petre (7th Baron Petre) (1689-1713), both of whom came from aristocratic Catholic families in Anglican England. Petre, passionate about Arabella, had cut a lock of her hair without permission. The ensuing argument led to a rift between the two families. In the poem, the loss of a lock of hair hits Belinda deeply, an allusion to how fragile beauty is. The names for the moons Ariel and Umbriel were also taken from this poem.
All the moons of Uranus are named after characters from William Shakespeare or Pope. The first four Uranus moons discovered ( Oberon , Titania , Ariel , Umbriel ) were named after suggestions by John Herschel , the son of the Uranus discoverer Wilhelm Herschel . Later the tradition of naming was retained.
Track properties
Orbit
Belinda orbits Uranus on a prograde , almost perfectly circular orbit at an average distance of around 75,255 km (approx. 2,944 Uranus radii) from its center, i.e. 49,697 km above its cloud ceiling. The orbital eccentricity is 0.00007, the web is 0.03063 ° to the equator of Uranus inclined .
Belinda is the eighth innermost of the Portia group , which also includes Bianca , Cressida , Desdemona , Juliet , Portia , Rosalind , Cupid and Perdita . These moons have similar orbits and similar spectral properties.
The orbit of the next inner moon Cupid is on average only 864 km away from Belinda's orbit, that of the next outer moon Perdita is 1,161 km away.
Belinda is located in the middle of two Uranus rings, the inner ν (Ny) dust ring , the outer edge of which is on average around 5,356 km from the Belinda orbit, and the inner edge of the outer μ (My) dust ring 10,750 km away.
Belinda orbits Uranus in 14 hours, 57 minutes and 52.77 seconds. Since this is faster than the rotation of Uranus, Belinda rises in the west and sets in the east as seen from Uranus. Since Belinda moves close to synchronous orbit, it turns out that Belinda only rises or sets once every 6.5 Uranus days on the horizon for a fictional observer, which means that she is in the sky for 3.25 Uranus days you can see.
rotation
It is believed that Belinda rotates synchronously and that its axis has an inclination of 0 °.
Physical Properties
Belinda has a mean diameter of 80.6 km. In the recordings of the Voyager-2 - probe Belinda appeared as highly elongated object having dimensions of 128 × 64 × 64 km, wherein the longitudinal axis is aligned with Uranus.
Its mean density of 1.3 g / cm 3 is significantly lower than the density of the earth and indicates that the moon is mainly composed of water ice .
Belinda has a very low albedo of 0.08, i.e. That is, 8% of the incident sunlight is reflected from the surface. It is therefore a very dark celestial body.
On its surface, the acceleration due to gravity is 0.0149 m / s 2 , which corresponds to about 1 ‰ of that on earth.
The mean surface temperature of Belinda is estimated to be between −184 ° and −209 ° C (89–64 K ).
The surface of Belinda appears gray in the spectrum .
exploration
Since the Voyager 2 space probe's flyby, the Uranus system has been studied intensively by both Earth-based observations and the Hubble Space Telescope . The orbit parameters of Belinda could be specified more precisely.
Web links
- IAUC 4164: Satellites of Uranus January 16, 1986 (discovery)
- IAUC 4165: Satellites of Uranus January 17, 1986 (Correction to IAUC 4164)
- IAUC 4609: Satellites of Saturn and Uranus June 8, 1988 (numbering and naming)
- Polish moon page: Belinda - description and further links (English)
- Satellite Viewer - orbit simulation of Uranus' moons