VDBERGH (N0): van den Bergh Reflection Nebulae Catalog; -28 < Dec (19950124)
FILES:
vdbergh.n0 (158 reflection nebulae)
vdbergh.n0n (associated note file)
vdbergh.ls (position-list for locating nebulae)
CONTENTS: van den Bergh Catalog of Reflection Nebulae; 1966
DATASET: This file comes in HyperSky dataset N-2, version 19950124. Availability on HyperSky CD-ROM: Vol. 2 (1995)
DESCRIPTION: This datafiles contains 158 reflection nebulae from the van den Bergh Reflection Nebulae Catalog. The catalog was originally published in 1966. The machine-readable version which serves as the basis for the present ADC catalog was obtained from the University of Maryland in 1974. Catalog sky coverage extends no further south than about -28 degrees Declination.
The HyperSky file is based on the version of the catalog available through the U.S. National Space Sciences Data Center (NSSDC) as Astronomical Data Center (ADC) catalog #7021.
DATA: The HyperSky datafile contains the following data from the catalog:
POSITION: Right Ascension and Declination are based on the catalog's galactic longitude and latitude positions, converted to equinox 1950 RA and Dec, and then precessed to equinox 2000. Catalog positions were provided to an accuracy of 0.1 degree in both galactic coordinates.
MAG: the V magnitude of the illuminating star.
IDENTIFICATION: The catalog's ven den Bergh number, prefixed by vdB.
COMMENTS: The comment line contains the following information, provided if available for each nebula:
* A line starting with "nebula size:" giving the approximate diameter of the nebula, derived from the radius value provided in the catalog. The values given are based on either or both of the two colors red and blue, as measured by the size of the nebula on the red and blue Palomar Sky Survey (PSS) plates.
* One or two lines identifying the star illuminating the nebula. The identification may include the Durchmusterung catalog name (BD = Bonner Durchmusterung, CD = Cordoba Durchmusterung), and the Henry Draper (HD) catalog number.
NOTEFILE: The associated notefile contains the following additional information on each nebula, provided if available:
* If appropriate, a comment indicating that the illuminating star is variable.
* A line giving the spectral type of the illuminating star.
* A line giving the nebula type, which can be one of the following basic types, or a combination of them.
Type I: A nebula in which the illuminating star is embedded in the nebulosity.
Type II: A nebula in which the illuminating star is located outside the illuminated nebulosity.
Type P: A peculiar nebula.
* A description of the nebula surface brightness on the blue Palomar Sky Survey (PSS) prints, as follows:
very bright
bright
moderate
faint
very faint
* A desription of the nebula color on the Palomar Sky Survey (PSS) prints, as follows:
very blue
blue
moderately blue
intermediate (equally bright on the blue and red PSS prints)
moderately red
red
very red
* A description of the absorption in the field containing reflection, as follows:
strong
moderate
weak
absent
POSITION-LIST: The position-list VDBERGH.LS, if loaded, will enable you locate any one of the catalog nebulae by name.
Remember that this is only a position-list; it does not actually display a nebula at the position you select. The nebula you select will appear at the position only if you have also loaded vdbergh.n0, or some other HyperSky catalog file which contains the nebula.
REFERENCES Astronomical Journal, 1966 (volume 71, pages 990-998).