(189396) Sielewicz Main-belt Asteroid
Discovered on 2 May 2008 by Cernis, K., Zdanavicius, J. at Moletai.
Henryk Sielewicz (b. 1949) is one of the most skilled Lithuanian amateur astronomers. He built an observatory in Lavariškės (25 km from Vilnius), where he carries out astrophotography and makes visual estimates of the brightness of comets. He has polished some 25 astronomical mirrors and made dozens of telescopes.Naming citation (WGSBN Bull. 6, #7, 5), IAU / Minor Planet Center, via NASA/JPL
Where Sielewicz is today
Seen from above the solar system on 2026-10-14: Sielewicz is 2.54 au from the Sun and 2.94 au from Earth. Computed from JPL's orbital elements.
Facts
| Number | 189396 |
| Provisional designation | 2008 JB6 |
| Orbit class | Main-belt Asteroid |
| Absolute magnitude (H) | 16.2 |
| Orbital period | 4.48 years |
| Semi-major axis | 2.72 au |
| Perihelion – aphelion | 2.52 – 2.91 au |
| Eccentricity | 0.0725 |
| Inclination | 6.92° |
| Closest distance between its orbit and Earth's (MOID) | 1.52 au |
Data: NASA/JPL Small-Body Database and the IAU Minor Planet Center.
Also named after someone called Henryk
All asteroids named after someone called Henryk