Discovered by Y. Väisälä MPC designation 1534 Näsi Observation arc 91.46 yr (33,406 days) Orbits Sun Named after Näsijärvi (Finnish lake) Asteroid group Asteroid belt | Discovery date 20 January 1939 Minor planet category main-belt · (middle) Discovered 20 January 1939 Discoverer Yrjö Väisälä Discovery site Iso-Heikkilä Observatory | |
Alternative names 1939 BK · 1933 UQ
1957 EA · 1960 UB
1962 JA · A915 VB
A924 WE · A924 YE People also search for 1530 Rantaseppä, 1542 Schalén | ||
1534 Näsi, provisional designation 1939 BK, is a carbonaceous asteroid from the middle region of the asteroid belt, approximately 20 kilometers in diameter. It was discovered on 20 January 1939, by Finnish astronomer Yrjö Väisälä at Turku Observatory in Southwest Finland.
Näsi orbits the Sun at a distance of 2.0–3.4 AU once every 4 years and 6 months (1,646 days). Its orbit has an eccentricity of 0.25 and an inclination of 10° with respect to the ecliptic. It was first identified as A915 VB at Simeiz Observatory in 1915. The body's observation arc begins 15 years prior to its official discovery with its identification as 1924 YE at Heidelberg Observatory.
In April 2007, the so-far best rated rotational light-curve of Näsi was obtained by Jason Sauppe at Oakley Observatory in the United States. The light-curve analysis gave a rotation period of 7.94 hours with a brightness variation of 0.35 magnitude (U=3-). Periods from other photometric observations were obtained by astronomers René Roy in May 2016 (5.98 hours, Δ0.47 mag, U=2+), Giovanni de Sanctis in the 1990s (9.75 hours, Δ0.22 mag, U=2), Adrián Galád in October 2005 (7.9338 hours, Δ0.51 mag, U=2-), and a period of 7.93161 hours modeled from various data sources and published in 2016 (U=n.a.).
In the SMASS taxonomy, the carbonaceous The C-type asteroid is also classified as a Cgh-subtype. According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite, and NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Näsi measures between 18.32 and 27.52 kilometers in diameter and its surface has an albedo between 0.035 and 0.100. The Collaborative Asteroid Lightcurve Link derives an albedo of 0.0721 and a diameter of 22.11 kilometers based on an absolute magnitude of 11.75.
This minor planet is named for the large Finnish lake Näsijärvi, sometimes called "Näsi". It measures 256 square kilometers (99 sq mi) in size and is located only 95 metres above sea level. Naming citation was published before November 1977 (M.P.C. 3929).