Ondrejov NEO Photometric Program - basic info

Institutes and instrumentation

This project is based on collaboration between researchers from Astronomical Institute of the Academy of Sciences of the Czech Republic and the Astronomical Institute of the Charles University Prague. Starting in 1993, it was supported by the ESO C&EE Programme, grant No. A-02-069, the Grant Agency of the Czech Republic, grant No. 205-95-1498, and currently by the Grant Agency of the Academy of Sciences of the Czech Republic, grant No. A3003708, and the Grant Agency of the Czech Republic, grant No. 205-99-0255. The 0.65-m/3.6 reflecting telescope equipped with the SBIG ST-8 CCD imaging camera in the primary focus and Johnson-Cousins BVRI filters is used for observing part of the project.

Targets of observations

Near-Earth Objects (NEOs) are minor bodies of the Solar System with perihelion distances < 1.3 AU. We concentrate mostly on near-Earth asteroids (NEAs); most of them are catastrophic disruption fragments of larger asteroids, but some of them may be inactive cometary nuclei. According to their perihelion distances (q) and semi-major axes (a), NEAs are formally divided into three groups: Atens (a< 1.0 AU), Apollos (a> 1.0 AU, q< 1.0 AU), and Amors (1.0 AU<q< 1.3 AU). See list of known NEAs.

The scientific interest in NEAs has several reasons:

Furthermore, they can be used as a source of raw materials in future activity in the interplanetary space.

Main scientific goal

The main goal of the Ondrejov NEO Photometric Program is to increase the sample of rotational and shape properties of near-Earth Asteroids. Knowledge of these properties is necessary for our understanding of origins and evolution of NEOs. The information on the rotation and shape is particularly important in cases in which the results of observations utilizing different techniques and wavelengths are combined, thus we aim to provide baseline data for further physical studies of NEAs.

Observing strategy

We try to obtain photometric lightcurve observations for most NEAs which make a favorable apparition in the northern celestial hemisphere. Typical limiting magnitude for good photometry with our system is about V=17.5, depending somewhat on the apparent motion of the asteroid. For a NEA with no information on its rotation available, we always try to observe it as much as needed to get an unambiguous result on its period, suppressing a bias against slow and low amplitude rotators. If the rotation period of a NEA is already known, we sometimes continue observations for a longer interval to obtain data potentially allowing a determination of the object's rotational pole. Broad-band colors and absolute magnitudes are also derived whenever possible.

Astrometry of NEAs - an additional task of our project

In addition to photometric observations, we do also astrometric observations of NEAs. We concentrate mostly on newly discovered objects, mostly from The NEO Confirmation Page), but astrometry is routinely done also on photometric series of NEAs. Astrometry is also made for objects of particular interest, as are those in conditions favorable for recovery.

Discoveries of main belt asteroids - a by-product

Naturally, we frequently find faint unknown asteroids in fields of observed NEAs. We try to follow-up and acquire enough data for determination of orbits for brighter of them. Several tens of our discoveries have already been numbered and more (a few hundreds) are candidates for numbering in future.

Basic information on asteroids:

See, e.g., the LPL's Nine Planets page.

Note on written form of Czech names:

Please, remember that some Czech names contain special diacritical marks. In LaTeX transcription, "Ondrejov" should be written as Ond\v{r}ejov, "Sarounova" as \v{S}arounov\'a, and "Kusnirak" as Ku\v{s}nir\'ak.

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