# 563 Suleika
**563 Suleika** (provisional designation A905 GD) is a large main-belt asteroid roughly 53 km in diameter, orbiting between Mars and Jupiter in the main portion of the asteroid belt[1](https://www.spacereference.org/asteroid/563-suleika-a905-gd). It is larger than 99% of asteroids, comparable in size to the U.S. state of [Rhode Island](https://www.edgepedia.org/rhode-island), and NASA JPL has not classified it as potentially hazardous because its orbit does not bring it close to Earth[1](https://www.spacereference.org/asteroid/563-suleika-a905-gd).
| Key fact | Detail |
|---|---|
| Class | Main-belt asteroid; not a near-Earth object and not a potentially hazardous object[1](https://www.spacereference.org/asteroid/563-suleika-a905-gd) |
| Size | About 53 km diameter (53.29 km per Space Reference; 53.6 km adopted for the 2023 occultation)[1](https://www.spacereference.org/asteroid/563-suleika-a905-gd) • [2](https://www.occultations.org.nz/planet/2023/updates/231201_563_82778_u.htm) |
| Orbit | Semimajor axis 2.712 AU, eccentricity 0.236, inclination 10.25 degrees; period 4.47 years (about 1,630 days)[3](https://astro.vanbuitenen.nl/minorplanet/Suleika) |
| Distance range | Perihelion 2.07 AU, aphelion 3.35 AU[1](https://www.spacereference.org/asteroid/563-suleika-a905-gd) |
| Rotation | 5.69 hours, with a lightcurve amplitude of 0.13 to 0.28 magnitudes[4](https://pmc.ncbi.nlm.nih.gov/articles/PMC7243944/) |
| Spectral type | S (Tholen) / Sl (SMASSII)[1](https://www.spacereference.org/asteroid/563-suleika-a905-gd) |
| Absolute magnitude | H = 8.38 (2010 solution) or 8.45 (2023 solution), with G = 0.15[5](https://www.occultations.org.nz/planet/2010/updates/101029_563_25586_u.htm) • [2](https://www.occultations.org.nz/planet/2023/updates/231201_563_82778_u.htm) |
## Orbit
With an orbital period of 1,630 days, roughly 4.46 years, Suleika circles the Sun at distances ranging from a perihelion of 2.07 AU to an aphelion of 3.35 AU.[1](https://www.spacereference.org/asteroid/563-suleika-a905-gd) The osculating elements at the 2026 epoch give a semimajor axis of 2.7122091 AU, an eccentricity of 0.2361504, an inclination of 10.24689 degrees, and an orbital period of 4.47 years[3](https://astro.vanbuitenen.nl/minorplanet/Suleika). An earlier solution computed for the 2010 occultation gave a semimajor axis of 2.71363362 AU, eccentricity 0.23338085, and inclination 10.23159789 degrees, based on 759 used observations spanning 1907 November 3 to 2010 September 9[5](https://www.occultations.org.nz/planet/2010/updates/101029_563_25586_u.htm).
## Rotation and photometry
The rotation of Suleika has been observed, and it completes a rotation on its axis every 5.69 hours[1](https://www.spacereference.org/asteroid/563-suleika-a905-gd). A 2017 lightcurve photometry opportunity listing gives the same 5.69-hour period with an amplitude of 0.13 to 0.28 magnitudes at magnitude 13.2 near opposition[4](https://pmc.ncbi.nlm.nih.gov/articles/PMC7243944/). Photoelectric lightcurves of Suleika, together with those of [68 Leto](https://www.edgepedia.org/68-leto), were published by Jean Surdej, an astronomer at the Institute of Astrophysics at the University of Liège, and H. J. Schober in *Astronomy and Astrophysics Supplement Series* in 1980, with UBV color and amplitude measurements[6](https://orbi.uliege.be/handle/2268/19146).
## Stellar occultations
Because a main-belt asteroid's shadow sweeps across Earth only along a narrow track, occultation predictions for Suleika are issued with explicit uncertainty ranges. The 2010 update gave a projected shadow path width of about 53 km moving at 2.8919 km/s, with a 1-sigma path uncertainty of plus or minus 1.24 path widths (about 21.8 seconds), and advised observers to watch within plus or minus 3 sigma of the updated path because larger errors have been observed[5](https://www.occultations.org.nz/planet/2010/updates/101029_563_25586_u.htm).
**The 2023 event.** On 2023 December 1 UT, the 54 km diameter asteroid occulted the 9.5-magnitude star HIP 770 in the constellation Cetus for observers along a path across south-eastern West Australia, north-western [South Australia](https://www.edgepedia.org/south-australia), and the [Northern Territory](https://www.edgepedia.org/northern-territory)[2](https://www.occultations.org.nz/planet/2023/updates/231201_563_82778_u.htm). The combined light of the asteroid and the star was predicted to drop by about 3.0 magnitudes to 12.37, the asteroid's own magnitude, for at most 4.9 seconds[2](https://www.occultations.org.nz/planet/2023/updates/231201_563_82778_u.htm). The event ran from about 12:32 to 12:49 UT, with the Moon 83% sunlit and 120 degrees from the target, and carried an event rank of 99, a measure of prediction reliability in which 100 indicates a very accurate prediction[2](https://www.occultations.org.nz/planet/2023/updates/231201_563_82778_u.htm). The star's position came from Gaia DR3, and the update used astrometry from the IAU Minor Planet Center together with data from the [European Space Agency](https://www.edgepedia.org/european-space-agency)'s Gaia mission[2](https://www.occultations.org.nz/planet/2023/updates/231201_563_82778_u.htm).
## Discovery and designation
Suleika was discovered in 1905 and carries the old-style provisional designation A905 GD[1](https://www.spacereference.org/asteroid/563-suleika-a905-gd); a compiled dataset lists the alternate form 1905 QK for the same object[7](https://gist.github.com/helderdarocha/3821377530d0102e6eb3f44bc5ac7480). It received the permanent number 563 in the early numbered series of main-belt asteroids[7](https://gist.github.com/helderdarocha/3821377530d0102e6eb3f44bc5ac7480).
## Observing
At the 2027 opposition on 29 July, Suleika is expected to reach magnitude 12.3 at a geocentric distance of 1.845 AU, bright enough for modest amateur telescopes; away from opposition it sits near magnitude 14.7[3](https://astro.vanbuitenen.nl/minorplanet/Suleika).
## References
1. [563 Suleika (A905 GD), Space Reference](https://www.spacereference.org/asteroid/563-suleika-a905-gd)
2. [RASNZ Occultation Section: Occultation by (563) Suleika, 2023 Dec 01](https://www.occultations.org.nz/planet/2023/updates/231201_563_82778_u.htm)
3. [(563) Suleika, astro.vanbuitenen.nl](https://astro.vanbuitenen.nl/minorplanet/Suleika)
4. [Lightcurve Photometry Opportunities: 2017 April-June, PMC](https://pmc.ncbi.nlm.nih.gov/articles/PMC7243944/)
5. [RASNZ Occultation Section: Suleika Occultation Update, 2010](https://www.occultations.org.nz/planet/2010/updates/101029_563_25586_u.htm)
6. [Surdej, J. and Schober, H. J. (1980). Rotation period and photoelectric lightcurves of asteroids 68 Leto and 563 Suleika, A&AS 41, 335-338, ORBi](https://orbi.uliege.be/handle/2268/19146)
7. [Solar system small-body dataset (sol_2019.json), GitHub gist](https://gist.github.com/helderdarocha/3821377530d0102e6eb3f44bc5ac7480)
---
*Topic: Encyclopedia › Places and geography › Extraterrestrial places › Small bodies of the Solar System › Main-belt asteroids and numbered minor planets › Middle-belt asteroids*
*Initially written Oct 21, 2026*
*Copyright 2026 EdgeChat AI, a subsidiary of Biostate AI.*
License: Edgepedia Community License 1.0, https://www.edgepedia.org/edgepedia/license