Catalog of asteroid positions and magnitudes from digit-ized photographic observations in Baldone (Latvia)

O.M. Yizhakevych1, I. Eglitis2, S.V. Shatokhina1, V.M. Andruk1, Yu. I. Protsyuk3

1Main Astronomical Observatory of National Academy of Sciences, Kyiv, Ukraine
22Baldone Observatory, Institute of Astronomy, University of Latvia, Raina blvd. 19, Riga, LV 1586, Latvia
3Research Institute "Mykolaiv Astronomical Observatory", Mykolaiv, Ukraine

The Baldone Observatory of the Institute of Astronomy of the Latvian University owns a photographic collection of 22,633 astronomical negatives obtained using 1.2 m Schmidt telescope (IAU code 069). Among them there are about 780 plates in the U photometric band and 4600 film negatives [2] in the V band, which are close to the Johnson's photometric system. The observational period started in 1966 and lasted for 39 years.

In 2013-2018, the Baldone Observatory performed regular digitization of photographic negatives [3]. The negatives were digitized using commercial Epson Expression 10000XL scanner with a resolution of 1200 dpi or 2400 dpi. The processing of digitized scans was carried out by the observers at the Bal-done Observatory, the Research Institute "Mykolaiv Astronomical Observatory" and the Main Astro-nomical Observatory of the National Academy of Sciences of Ukraine. The U and V magnitude data of stars and galaxies will be used as a photometric supplement to the Northern Sky Survey project [1, 4]. At present, 281 plates and 2167 film negatives exposed in U and V photometric ranges have been used to asteroid searching.

Based on the scan processing results, a catalog of 1848 topocentric positions and magnitudes of aster-oids and comets was compiled. It includes 1678 and 170 positions and magnitudes from observations in the V and U bands, respectively. It also contains seven positions and magnitudes of comets. Such images of asteroids, which were recorded on photographic negatives in the immediate vicinity of im-ages of stars from the Gaia DR2 catalog, were excluded from the compiled catalog. We considered them to be ambiguous identifications of images of asteroids.

Astrometric and photometric reduction of digitized astronomical negatives is performed in the Tycho-2 reference system and photoelectric standards, respectively. Additional data to the catalog contain the values of the rms errors in determining the equatorial coordinates and magnitudes of the Tycho-2 ref-erence stars for each plate. A preliminary analysis of the catalog data is described in detail in articles [5, 6]. The comparison results of the asteroid positions with the JPL ephemeris ( are presented by histograms of O-C differences in the following figures.

Data description:

              Right ascension and declination: ICRF/J2000.0 	           


 FileName                Lrecl  Records  Explanations
ReadMe                    80             This file
ASTEROIDS_Baldone.dat     91     1848    Catalog of the topocentric positions 
                                         and magnitudes of asteroids and comets
ADD_ASTEROIDS_Baldone.dat 23     554     Additional data to the Catalog

Byte-by-byte Description of files: ASTEROIDS_Baldone.dat
 Bytes Format   Units           Explanations
 01-05   I5     number          Plate number according to plate archive
 07-07   A1     band            Photometric band V or U
 09-12   I4     year            UTC date of observation, year
 14-15   I2     month           UTC date of observation, month
 17-25   F9.6   day             UTC date of observation, day
 27-35   A9     name            Name of an asteroid or a comet
 37-38   I2     hour            Right Ascension J2000, hours
 40-41   I2     minute          Right Ascension J2000, minutes
 43-48   F6.3   second          Right Ascension J2000, seconds
 50-50   A1     ----            Sign of Declination J2000
 51-52   I2     degree          Declination J2000, degrees
 54-55   I2     arcmin          Declination J2000, arcminutes
 57-61   F5.2   arcsec          Declination J2000, arcseconds
 63-67   F5.2   mag             V or U magnitude of the asteroid
 69-73   F5.2   arcsec          Diameter of the asteroid image, arcseconds
 75-79   F5.2   arcsec          Difference (O-C)RA =15*(O-C)RAcos(DEC), 
 81-85   F5.2   arcsec          Difference (O-C)DEC, arcseconds
 87-91   F5.2   mag             Difference V-Mv or U-Mv, magnitude,
                                Mv-apparent visual asteroid magnitude 
                                calculated by JPL ephemeris)  

Byte-by-byte Description of file: ADD_ASTEROIDS_Baldone.dat
 Bytes  Format  Units           Explanations
 01-05   I5     number          Plate number according to plate ar-chive
 07-11   f5.2   arcsec          Root mean square error, Right Ascen-sion
 13-17   f5.2   arcsec          Root mean square error, Declination
 19-23   f5.2   mag             Root mean square error, V or U magni-tude

Data (171 Kb).File: ASTEROIDS_Baldone.dat.

Data (13 Kb).File: ADD_ASTEROIDS_Baldone.dat.

Alternative links:

Data (171 Kb).File: ASTEROIDS_Baldone.dat.

Data (13 Kb).File: ADD_ASTEROIDS_Baldone.dat.


1. Andruk, V.; Yuldoshev, Q.; Eglitis, I.; Pakuliak, L.; Mullo-Abdolov, A.; Vavilova, I.; Protsyuk, Yu.; Relke, H.; Golovnia, V.; Shatokhina, S.; Yizhakevych, O.; Ehgamberdiev, Sh.; Muminov, M.; Kokhirova, G.; Kazantseva, L. On the Concept of the Enhanced FON Catalog Compilation, Odessa Astron. Publ., 2017, vol. 30, p.159

2. Eglite, M.; Eglitis, I. Baldone Schmidt (Latvia) Telescope Astrophotos Archive, Odessa Astron. Publ., 2016, vol. 29, p.120

3. Eglitis, I.; Andruk, V. Processing of Digital Plates1.2m of Baldone Observatory Schmidt Tele-scope, Open Astronomy, 2017, vol. 26, is.1, p.7

4. Eglitis, I.; Eglite, V.; Andruk, V.; Protsyuk, Yu.; Protsyuk, S.; Kovylianska, O. Baldone 1.2m Telescope Plate Archive - Hidden Reserves of the FON Project, Odessa Astron. Publ., 2018, vol. 31, p. 208

5. Eglitis, I.; Eglite, M.; Shatokhina, S. V.; Andruk, V. M. Obtaining Positions of Asteroids from Digitized Processing of Photographic Observations in Baldone Observatory (Code 069), Odessa Astron. Publ., 2016, vol. 29, p.123

6. Eglitis, I.; Yizhakevych, O.; Shatokhina, S.; Protsyuk, Yu.; Andruk, V., Asteroid Search Results for Digitized Astroplates of 1.2m Telescope in Baldone, Odessa Astron. Publ., 2019, vol. 32, p.189

Photographic Survey of the Northern Sky (Фотографічний огляд Північного неба - ФОН)

Catalogues of Astrometric Positions and Photometric Stellar Magnitudes of SS Bodies (Каталоги астрометричних положень та фотометричних зоряних величин тіл Сонячної системи)

Astrometric and Photometric Catalogues for research in stellar kinematics (Астрометричні та фотометричні каталоги для зоряно-кінематичних досліджень)

Catalogues of Positions and Orbital Elements of Geosynchronous Space Objects (Каталоги положень та орбітальних елементів геосинхронних небесних об'єктів)

L.Pakuliak. Questions, remarks and propositions are welcome.