Digitized First Byurakan Survey - DFBS







First Byurakan Survey

                            Technical data

                            FBS zones statistics

                            Markarian galaxies

                            FBS based projects




                            About DFBS






                            Sample spectra

                            Data visualization

                            Science with DFBS


                            DFBS at Roma

Virtual Observatories

                            Armenian VO





Other related links

                            Armenian Astronomy

                            Byurakan Observatory





Digitization products at BAO

Digitized First Byurakan Survey – DFBS

The final products of the DFBS project are:

DFBS database, containing all 2000 FBS plates (180 MB each), 2D and 1D spectra of all objects present;

DFBS catalog, containing the list of all 20,000,000 objects present in the FBS plates with their positional, photometric and spectral information, as well as cross-matching with objects from other available catalogs (MAPS, USNO-B1.0, ROSAT, 2MASS, IRAS, NVSS, FIRST).

Digitized Second Byurakan Survey – DSBS

The Second Byurakan Survey (SBS) was carried out by Markarian, Stepanian, Erastova, Lipovetski, Chavushyan, and Balayan in 1978-1991 on the Byurakan Observatory 102/132/213cm Schmidt telescope with 1.5, 3 and 4 prisms, in combination with hyper sensitized Kodak IIIaJ and IIIaF plates and filters, giving different ranges of spectrum (3500-5400A, 4950-5400A and 6300-6950A, respectively) (Markarian & Stepanian 1983, Stepanian 1996). In all, 550 plates have been obtained in 65 fields, 4x4 each. SBS covers 965 deg2 area at high galactic latitudes (|b|>30) with 07h43m<a<17h15m and +49<d<+61. The limiting magnitude differs in the range of 18m-20 m in V, and the survey is complete to 17.5 m. 7 fields (covering 112 deg2) have limiting magnitudes 19.5 m -20 m (so-called Selected or Deep Fields of the SBS), and are of special interest. The dispersion near H-g for spectra obtained with 1.5, 3 and 4 prisms is 1800A/mm, 900A/mm, and 280A/mm, respectively (and 1000A/mm near H-a for the 4 prism). SBS covers 3 zones of the FBS, with central declinations +51, +55 and +59. In average, each SBS plate contains low-dispersion spectra of some 50,000 objects, and there are some 3,000,000 objects in the whole survey.

Since 2003, the digitization of the SBS has been started in parallel with the DFBS project. The scanning photometric range is 16 bit, scanning resolution is 2400 dpi (getting 10m pixel size). 180 SBS plates have been scanned so far.

Digitized 2.6m photographic spectra

Scanning of the 2.6m photographic spectra obtained in 1987-1991 by H.V. Abrahamian, A.M. Mickaelian and K.S. Gigoyan. Scanning resolution is 1600 dpi, photometric range: 16 bit. The result is some 700 650x21 pix size spectra of the FBS blue stellar objects & late-type stars. A new PN (FBS 2323+421), 7 white dwarfs (DA, DAB, DZ), 78 hot subdwarfs, 9 HBB stars have been revealed so far among the 101 published.

The 2D spectra are brought to a standard form for automatic reduction with a dedicated macro in MIDAS extbaophot.prg.





Examples of a HBB star, sdB hot subdwarf, DA white dwarf, and a planetary nebula (PN).

Coma cluster plates

Photographic plates for search for variable (flare) stars have been obtained in young stellar clusters. Photographic chains have been obtained by means of shifting the telescope in R.A. for each exposure, thus giving a possibility to compare the consequent 6-10 images of the same object. One of the clusters is the Coma, where 189 plates with a total number of more than 1200 exposures in 1965-1976 have been obtained by L.K. Erastova with the Byurakan 21 and 40 Schmidt telescopes. The famous blazer ON 231 is in the field giving a chance for study of its intraday variability. All these plates have been digitized, and the study of variability of ON 231 is active.

A piece of the Coma cluster plate with stellar chains and the 1D cut of 10 consequent images of one of the stars.

Armenian Virtual Observatory – ArVO

Some projects based on the DFBS have been already put forward, including search for new QSOs and other AGN, continuation of the FBS Second Part, identifications of IR and X-ray sources, etc. The DFBS is the basis for the Armenian Virtual Observatory (ArVO), which is being created at present and will unify all available astronomical data in Armenia, including all Byurakan archive and data from the Byurakan telescopes. ArVO will be a part of the International Virtual Observatories Alliance (IVOA).




For further info and use of the DFBS contact Dr. Areg Mickaelian

2002-2004 Digitized First Byurakan Survey