164 Eva is a
main-belt
The asteroid belt is a torus-shaped region in the Solar System, centered on the Sun and roughly spanning the space between the orbits of the planets Jupiter and Mars. It contains a great many solid, irregularly shaped bodies called asteroids ...
asteroid
An asteroid is a minor planet—an object larger than a meteoroid that is neither a planet nor an identified comet—that orbits within the Solar System#Inner Solar System, inner Solar System or is co-orbital with Jupiter (Trojan asteroids). As ...
that was discovered by the French brothers
Paul Henry and Prosper Henry
Paul-Pierre Henry (21 August 1848 – 4 January 1905) and his brother Prosper-Mathieu Henry (10 December 1849 – 25 July 1903) were French opticians and astronomers.
They made refracting telescopes and instruments for observatories, and were ...
on July 12, 1876, in Paris. The reason the name Eva was chosen remains unknown, though
Karl Ludwig Littrow suspected a "worldly origin" (''"Mit dem Namen könnten wir wie bei
Miriam
Miriam (, lit. ‘rebellion’) is described in the Hebrew Bible as the daughter of Amram and Jochebed, and the older sister of Moses and Aaron. She was a prophetess and first appears in the Book of Exodus.
The Torah refers to her as "Miria ...
wieder den biblischen Boden zu betreten glauben, wenn wir bei diesem Entdecker nicht an Taufen weltlichen Ursprungs gewöhnt wären"'').
The
orbital elements
Orbital elements are the parameters required to uniquely identify a specific orbit. In celestial mechanics these elements are considered in two-body systems using a Kepler orbit. There are many different ways to mathematically describe the same o ...
for 164 Eva were published in 1877 by American astronomer
Winslow Upton.
It is categorized as a
C-type asteroid
C-type (carbonaceous ) asteroids are the most common variety, forming around 75% of known asteroids. They are volatile-rich and distinguished by a very low albedo because their composition includes a large amount of carbon, in addition to rocks ...
and is probably composed of primitive
carbonaceous Carbonaceous refers to something relating to, containing, or composed of carbon. It is a descriptor used for the attribute of any substance rich in carbon. Particularly, ''carbonaceous hydrocarbons'' are very unsaturated, high- molecular-weight h ...
chondritic
A chondrite is a stony (non-metallic) meteorite that has not been modified by either melting or differentiation of the parent body. They are formed when various types of dust and small grains in the early Solar System accreted to form primiti ...
materials.
Photometric observations of this asteroid at the Palmer Divide Observatory in
Colorado Springs, Colorado
Colorado Springs is the most populous city in El Paso County, Colorado, United States, and its county seat. The city had a population of 478,961 at the 2020 United States census, 2020 census, a 15.02% increase since 2010 United States Census, 2 ...
, during 2008 gave a
light curve
In astronomy, a light curve is a graph (discrete mathematics), graph of the Radiance, light intensity of a celestial object or region as a function of time, typically with the magnitude (astronomy), magnitude of light received on the ''y''-axis ...
with a period of 13.672 ± 0.003 hours and a small brightness variation of 0.04 ± 0.01 in
magnitude
Magnitude may refer to:
Mathematics
*Euclidean vector, a quantity defined by both its magnitude and its direction
*Magnitude (mathematics), the relative size of an object
*Norm (mathematics), a term for the size or length of a vector
*Order of ...
. This is consistent with a previous study reported in 1982 that listed a period estimate of 13.66 hours.
Between 2000 and 2021, 164 Eva has been observed to
occult
The occult () is a category of esoteric or supernatural beliefs and practices which generally fall outside the scope of organized religion and science, encompassing phenomena involving a 'hidden' or 'secret' agency, such as magic and mysti ...
fourteen stars.
With a perihelion of 1.718 AU 164 Eva is the closest asteroid over 100 kilometers to approach the
orbit of Mars
Mars has an orbit with a semimajor axis of 1.524 astronomical units (228 million km) (12.673 light minutes), and an orbital eccentricity, eccentricity of 0.0934.Jean Meeus, ''Astronomical Formulæ for Calculators''. (Richmond, VA: Willmann-Bell ...
. Its closest approach is about 0.05 AU or about 19.5 lunar distances.
NASA.gov
/ref>
References
External links
Lightcurve plot of 164 Eva
Palmer Divide Observatory, '' B. D. Warner'' (2008)
Asteroid Lightcurve Database (LCDB)
query form
)
Dictionary of Minor Planet Names
Google books
– Observatoire de Genève, Raoul Behrend
– Minor Planet Center
*
*
Background asteroids
Eva
Eva
CX-type asteroids (Tholen)
X-type asteroids (SMASS)
18760712
Objects observed by stellar occultation
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