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:
They are the smallest bodies which are observable from the Earth, allowing
to study objects in otherwise unreachable size range.
Their origin and evolutional history represent an important source
of information on the processes in the Solar System.
Impacts of such bodies on the Earth's surface represent a hazard for
the Earth's biosphere. See
The Spaceguard Survey report.
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.
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.
