1021 Flammario, provisional designation , is a dark background

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 ...

from the central regions of the

asteroid 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 ...

, approximately in diameter. It was discovered on 11 March 1924, by German astronomer

Max Wolf Maximilian Franz Joseph Cornelius Wolf (21 June 1863 – 3 October 1932) was a German astronomer and a pioneer in the field of astrophotography. He was the chairman of astronomy at the University of Heidelberg and director of the Heidelberg-K� ...

at the

Heidelberg-Königstuhl State Observatory Heidelberg-Königstuhl State Observatory () is a historic astronomical observatory located near the summit of the Königstuhl hill in the city of Heidelberg in Germany. It is operated by the ''Center for Astronomy (ZAH)'' at the University of He ...

in Heidelberg, Germany. The asteroid was named after French astronomer

Camille Flammarion Nicolas Camille Flammarion FRAS (; 26 February 1842 – 3 June 1925) was a French astronomer and author. He was a prolific author of more than fifty titles, including popular science works about astronomy, several notable early science fiction ...

. The uncommon

F-type asteroid F-type asteroids are a relatively uncommon type of carbonaceous asteroid, falling into the wider C-type asteroid#C-group asteroids, C-group. Characteristics F-type asteroids have spectra generally similar to those of the B-type asteroid, B-type ...

has a

rotation period In astronomy, the rotation period or spin period of a celestial object (e.g., star, planet, moon, asteroid) has two definitions. The first one corresponds to the '' sidereal rotation period'' (or ''sidereal day''), i.e., the time that the objec ...

of 12.16 hours.

Orbit and classification

''Flammario'' is a non-

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

asteroid from the main belt's background population. It orbits the Sun in the central asteroid belt at a distance of 2.0–3.5 AU once every 4 years and 6 months (1,654 days;

semi-major axis In geometry, the major axis of an ellipse is its longest diameter: a line segment that runs through the center and both foci, with ends at the two most widely separated points of the perimeter. The semi-major axis (major semiaxis) is the longe ...

of 2.74 AU). Its orbit has an

eccentricity Eccentricity or eccentric may refer to: * Eccentricity (behavior), odd behavior on the part of a person, as opposed to being "normal" Mathematics, science and technology Mathematics * Off-Centre (geometry), center, in geometry * Eccentricity (g ...

of 0.29 and an

inclination Orbital inclination measures the tilt of an object's orbit around a celestial body. It is expressed as the angle between a reference plane and the orbital plane or axis of direction of the orbiting object. For a satellite orbiting the Eart ...

of 16 ° with respect to the

ecliptic The ecliptic or ecliptic plane is the orbital plane of Earth's orbit, Earth around the Sun. It was a central concept in a number of ancient sciences, providing the framework for key measurements in astronomy, astrology and calendar-making. Fr ...

. The asteroid was first observed as at Taunton Observatory in February 1910. The body's

observation arc In observational astronomy, the observation arc (or arc length) of a Solar System body is the time period between its earliest and latest observations, used for tracing the body's path. It is usually given in days or years. The term is mostly use ...

begins at the

Pulkovo Observatory The Pulkovo Astronomical Observatory (), officially named the Central Astronomical Observatory of the Russian Academy of Sciences at Pulkovo, is the principal astronomical observatory of the Russian Academy of Sciences. It is located 19 km south ...

near Saint Petersburg, Russia, in January 1928, more than four years after its official discovery observation at Heidelberg.

Physical characteristics

In the

SMASS classification An asteroid spectral type is assigned to asteroids based on their reflectance spectrum, color, and sometimes albedo. These types are thought to correspond to an asteroid's surface composition. For small bodies that are not internally different ...

, ''Flammario'' is a "bright" carbonaceous B-type, while it is an uncommon

in the Tholen taxonomy. (The SMASS taxonomic scheme classifies all F-types as B-type asteroids). More recent

polarimetric Polarimetry is the measurement and interpretation of the polarization of transverse waves, most notably electromagnetic waves, such as radio or light waves. Typically polarimetry is done on electromagnetic waves that have traveled through or hav ...

observations also characterized the asteroid as a dark F-type.

Rotation period

Several rotational

lightcurve 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 ...

s of ''Flammario'' have been obtained from photometric observations since the 1990s (). Analysis of the best-rated lightcurve obtained by French amateur astronomer

Laurent Bernasconi This is a list of minor-planet discoverers credited by the Minor Planet Center with the discovery of one or several minor planets (such as near-Earth object, near-Earth and main-belt asteroids, Jupiter trojans and Distant minor planet, distant ob ...

in January 2005 gave a

of 12.160 hours with a consolidated brightness amplitude between 0.14 and 0.40

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 ...

().

Poles

In 2016, a modeled lightcurve using photometric data from various sources, rendered a similar sidereal period of 12.15186 hours and two spin axes of (32.0°, 22.0°) and (216.0°, 55.0°) in

ecliptic coordinates In astronomy, the ecliptic coordinate system is a celestial coordinate system commonly used for representing the apparent positions, orbits, and pole orientations of Solar System objects. Because most planets (except Mercury) and many small So ...

Diameter and albedo

According to the surveys carried out by the Infrared Astronomical Satellite

IRAS The Infrared Astronomical Satellite (Dutch language, Dutch: ''Infrarood Astronomische Satelliet'') (IRAS) was the first space telescope to perform a astronomical survey, survey of the entire night sky at infrared wavelengths. Launched on 25 Janu ...

, the Japanese Akari satellite and the

NEOWISE Wide-field Infrared Survey Explorer (WISE, observatory code C51, Explorer 92 and MIDEX-6) was a NASA infrared astronomy space telescope in the Explorers Program launched in December 2009.. . WISE discovered thousands of minor planets and nu ...

mission of NASA's

Wide-field Infrared Survey Explorer Wide-field Infrared Survey Explorer (WISE, List of observatory codes, observatory code C51, Explorer 92 and MIDEX-6) was a NASA infrared astronomy Space observatory, space telescope in the Explorers Program launched in December 2009.. . WISE L ...

, ''Flammario'' measures between 84.78 and 105 kilometers in diameter and its surface has a low

albedo Albedo ( ; ) is the fraction of sunlight that is Diffuse reflection, diffusely reflected by a body. It is measured on a scale from 0 (corresponding to a black body that absorbs all incident radiation) to 1 (corresponding to a body that reflects ...

between 0.04 and 0.05. The ''Collaborative Asteroid Lightcurve Link'' adopts the results obtained by IRAS, that is, an albedo of 0.0458 and a diameter of 99.39 kilometers based on an absolute magnitude of 8.98.

Mass, density and porosity

Fienga et al. estimated the mass of ''Flammario'' as (8.6 ± 3.87/2.84) kg, with a theoretical bulk density of 1.606 ± 0.722/0.529 g/cm.

Small Solar System bodies A small Solar System body (SSSB) is an object in the Solar System that is neither a planet, a dwarf planet, nor a natural satellite. The term was first IAU definition of planet, defined in 2006 by the International Astronomical Union (IAU) as fo ...

may have 20% of more porosity (which decreases with the size of the body due to self-gravity). The carbonaceous outer-belt asteroids typically show a higher macroporosity than the basaltic, stony asteroids from the inner regions of the asteroid belt.

Naming

This

minor planet According to the International Astronomical Union (IAU), a minor planet is an astronomical object in direct orbit around the Sun that is exclusively classified as neither a planet nor a comet. Before 2006, the IAU officially used the term ''minor ...

was named after renowned French astronomer

(1842–1925), who founded the French Astronomical Society () and the astronomical journal ''

L'Astronomie ''LAstronomie'' () is a monthly astronomy magazine published by the Société astronomique de France (SAF). Sylvain Bouley, the president of SAF, is the publication director and astronomer Fabrice Mottez is the editor-in-chief. History The magaz ...

'' in the 1880s. The official naming citation was mentioned in ''

The Names of the Minor Planets Paul Herget (January 30, 1908 – August 27, 1981) was an American astronomer and director of the Cincinnati Observatory, who established the Minor Planet Center after World War II. Career Herget taught astronomy at the University of Cincinna ...

'' by

Paul Herget Paul Herget (January 30, 1908 – August 27, 1981) was an American astronomer and director of the Cincinnati Observatory, who established the Minor Planet Center after World War II. Career Herget taught astronomy at the University of Cincinna ...

in 1955 (). The lunar crater ''

Flammarion Flammarion may refer to: * Camille Flammarion (1842–1925), French astronomer and author * Gabrielle Renaudot Flammarion (1877–1962), French astronomer, second wife of Camille Flammarion * Sylvie Flammarion (1836-1919), French feminist and paci ...

'' as well as the crater ''

'' on Mars were also named in his honor.

References

External links

Asteroid Lightcurve Database (LCDB)
query form

)
Dictionary of Minor Planet Names
Google books

– ''Geneva Observatory'',

Raoul Behrend This is a list of minor-planet discoverers credited by the Minor Planet Center with the discovery of one or several minor planets (such as near-Earth and main-belt asteroids, Jupiter trojans and distant objects). , the discovery of 612,011 nu ...

Discovery Circumstances: Numbered Minor Planets (1)-(5000)
– Minor Planet Center * * {{DEFAULTSORT:Flammario 001021 Discoveries by Max Wolf Named minor planets 001021 001021 19240311