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ANSUVPSCAT - ANS Ultraviolet Photometry Catalog of Point Sources

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Overview

All reliable observations of point sources with the ultraviolet photometer onboard the Astronomical Netherlands Satellite (ANS) operating between the October 1974 and April 1976 are presented. Extended objects, non-detected objects, and objects at the edges of the instrument's field of view have been omitted. The catalog contains 3573 objects, mostly stars (the total ANS UV database contained 4800 observed positions). The ANS satellite observed in five UV channels centered around 150, 180, 220, 250 and 330 nm (1500, 1800, 2200, 2500 and 3300 Angstroms). The characteristics of the ANS UV photometric bands are:
  Band designation             15N     15W     18      22      25      33
  -------------------------------------------------------------------------
  Central wavelength (nm)     154.5   154.9   179.9   220.0   249.3   329.4
  Bandwidth          (nm)       5.0    14.9    14.9    20.0    15.0    10.1
The reported magnitudes were obtained from mean count rates converted to fluxes using the ANS absolute calibration of Wesselius et al. (1980A&A....85..221W). In addition to the ultraviolet magnitudes, the catalog contains positions taken from the satellite pointing, spectral types, and UBV data from other sources as well as comments on duplicity, variability, and miscellaneous notes concerning individual objects.

Within the ANS photometric system, the UV magnitudes of different objects are comparable down to a level of 0.5-1.0%. Several studies on the intercomparison of all ANS data, and on the comparison of the ANS data with stellar models, with other UV satellites, and with the expected UV fluxes on the basis of ground-based information alone suggest that the ANS photometric system is well-established, and has, in particular, a linear dynamic range of at least a factor of 20,000. In these two respects, repeatability and dynamic range, the ANS UV instrument far exceeded all other UV missions then extant, e.g., TD-S2/68, OAO-WEP, and IUE. Of course, ANS had a much poorer spectral resolution, about 15 nm (150 Angstroms), than the other instruments.


Catalog Bibcode

1982A&AS...49..427W

References

ANS UV Photometry Catalogue of Point Sources
     Wesselius P.R., van Duinen R.J., de Jonge A.R.W., Aalders J.W.G.,
     Luinge W., Wildeman K.J.
    <Astron. Astrophys. Suppl. Ser. 49, 427 (1982)>
    =1982A&AS...49..427W

Provenance

This table was created by the HEASARC in September 2011 based on CDS Catalog II/97 file ans.dat.

Parameters

Name
A common name for the object. The designation was assigned per the following prioritized order: (1) for stars: the Henry Draper (HD) number, the Durchmusterung (DM) identification, then other names (2) for nebular objects: the NGC number, the IC number, then other names.

RA
The Right Ascension of the position of the object as transmitted to the satellite for the observation, in the selected equinox. This was given in B1950 coordinates to a precision of 1 second of time in the original table.

Dec
The Declination of the position of the object as transmitted to the satellite for the observation, in the selected equinox. This was given in B1950 coordinates to a precision of 0.1 arcminutes in the original table.

LII
The Galactic Longitude of the position of the object.

BII
The Galactic Latitude of the position of the object.

Spect_Type
The spectral type of the object, if a star. MK (or HD) spectral types are taken from the following sources, in the following priority order:

      1. Jaschek's selected spectral types (1978, Cat. <III/42>);
      2. Houk and Cowley (1975, Cat. <III/31>; 1978, Cat. <III/51>);
      3. Buscombe's catalogs (1977, 3rd edition; 1980, 4th edition;
                 Evanston, Illinois, USA);
      4. or from the HD Catalog (Cat. <III/135>).
  
The format of the MK type is reasonably standard, except that, for stars from the HD Catalog, a suffix of HD replaces the luminosity part of the MK type, e.g., 'A0 HD'.

Vmag
The V-band (visual or photoelectric) magnitude of the object. The magnitudes are taken from:

      1. Nicolet's homogenized UBV Catalog (1978A&AS...34....1N)
      2. The "Catalog of Stellar Identifications" (CSI, see Ochsenbein et
         al., 1981A&AS...43..259O) where mv is estimated from mpg
         and HD spectral type, or
      3. from other sources.
  
Note that visual magnitude values (entries with the vmag_flag parameter set to 'V') are reported to lower precision (one decimal place) then the photoelectric V magnitudes (two decimal places; vmag_flag set to 'P').

Vmag_Flag
The type of V-band (visual or photoelectric) magnitude of the object. Note that visual magnitude values are derived from photographic magnitudes using the spectral type information to correct for the different bandpass. Such cases have values set to 'V' and are reported to lower precision (one decimal place) then the photoelectric V magnitudes (two decimal places) which have vmag_flag set to 'P'.

BV_Color
The B-V color index of the object. The magnitudes are taken from:

      1. Nicolet's homogenized UBV Catalog (1978A&AS...34....1N)
      2. The "Catalog of Stellar Identifications" (CSI, see Ochsenbein et
         al., 1981A&AS...43..259O) where mv is estimated from mpg
         and HD spectral type, or
      3. from other sources.
  

UB_Color
The U-B color index of the object. The magnitudes are taken from:

      1. Nicolet's homogenized UBV Catalog (1978A&AS...34....1N)
      2. The "Catalog of Stellar Identifications" (CSI, see Ochsenbein et
         al., 1981A&AS...43..259O) where mv is estimated from mpg
         and HD spectral type, or
      3. from other sources.
  

Mag_N1550_A_Limit
This flag parameter is set to '>' to indicate that the corresponding magnitude value is an upper limit (S/N < 3) rather than a detection.

Mag_N1550_A
The magnitude of the object in the 15N band around 155 +/- 5 nm. Magnitudes m are defined as m = -2.5*log F - 26.10, where F is the flux in W/m2/nm. Mean count rates are converted to fluxes using the ANS absolute calibration given by Wesselius et al. (1980A&A....85..221W) and the fluxes used to derive the magnitudes reported.

Mag_N1550_A_Error
The error in the corresponding magnitude value, in magnitudes. If the corresponding magnitude is an upper limit rather than a detection, this field is left blank. See section 6.1.3 of the reference paper for a discussion as to how the magnitude errors were estimated.

Mag_W1550_A_Limit
This flag parameter is set to '>' to indicate that the corresponding magnitude value is an upper limit (S/N < 3) rather than a detection.

Mag_W1550_A
The magnitude of the object in the 15W band around 155 +/- 15 nm. Magnitudes m are defined as m = -2.5*log F - 26.10, where F is the flux in W/m2/nm. Mean count rates are converted to fluxes using the ANS absolute calibration given by Wesselius et al. (1980A&A....85..221W) and the fluxes used to derive the magnitudes reported.

Mag_W1550_A_Error
The error in the corresponding magnitude value, in magnitudes. If the corresponding magnitude is an upper limit rather than a detection, this field is left blank. See section 6.1.3 of the reference paper for a discussion as to how the magnitude errors were estimated.

Mag_1800_A_Limit
This flag parameter is set to '>' to indicate that the corresponding magnitude value is an upper limit (S/N < 3) rather than a detection.

Mag_1800_A
The magnitude of the object in the 18 band around 180 +/- 15 nm. Magnitudes m are defined as m = -2.5*log F - 26.10, where F is the flux in W/m2/nm. Mean count rates are converted to fluxes using the ANS absolute calibration given by Wesselius et al. (1980A&A....85..221W) and the fluxes used to derive the magnitudes reported.

Mag_1800_A_Error
The error in the corresponding magnitude value, in magnitudes. If the corresponding magnitude is an upper limit rather than a detection, this field is left blank. See section 6.1.3 of the reference paper for a discussion as to how the magnitude errors were estimated.

Mag_2200_A_Limit
This flag parameter is set to '>' to indicate that the corresponding magnitude value is an upper limit (S/N < 3) rather than a detection.

Mag_2200_A
The magnitude of the object in the 22 band around 220 +/- 20 nm. Magnitudes m are defined as m = -2.5*log F - 26.10, where F is the flux in W/m2/nm. Mean count rates are converted to fluxes using the ANS absolute calibration given by Wesselius et al. (1980A&A....85..221W) and the fluxes used to derive the magnitudes reported.

Mag_2200_A_Error
The error in the corresponding magnitude value, in magnitudes. If the corresponding magnitude is an upper limit rather than a detection, this field is left blank. See section 6.1.3 of the reference paper for a discussion as to how the magnitude errors were estimated.

Mag_2500_A_Limit
This flag parameter is set to '>' to indicate that the corresponding magnitude value is an upper limit (S/N < 3) rather than a detection.

Mag_2500_A
The magnitude of the object in the 25 band around 250 +/- 15 nm. Magnitudes m are defined as m = -2.5*log F - 26.10, where F is the flux in W/m2/nm. Mean count rates are converted to fluxes using the ANS absolute calibration given by Wesselius et al. (1980A&A....85..221W) and the fluxes used to derive the magnitudes reported.

Mag_2500_A_Error
The error in the corresponding magnitude value, in magnitudes. If the corresponding magnitude is an upper limit rather than a detection, this field is left blank. See section 6.1.3 of the reference paper for a discussion as to how the magnitude errors were estimated.

Mag_3300_A_Limit
This flag parameter is set to '>' to indicate that the corresponding magnitude value is an upper limit (S/N < 3) rather than a detection.

Mag_3300_A
The magnitude of the object in the 33 band around 330 +/- 10 nm. Magnitudes m are defined as m = -2.5*log F - 26.10, where F is the flux in W/m2/nm. Mean count rates are converted to fluxes using the ANS absolute calibration given by Wesselius et al. (1980A&A....85..221W) and the fluxes used to derive the magnitudes reported.

Mag_3300_A_Error
The error in the corresponding magnitude value, in magnitudes. If the corresponding magnitude is an upper limit rather than a detection, this field is left blank. See section 6.1.3 of the reference paper for a discussion as to how the magnitude errors were estimated.

Num_Obs
The number of separate pointings in the 25 band. Usually this number applies to all observation bands; however, at 15N and 15W the number can be smaller because the band was used in either the wide (15 nm) or the narrow (5 nm) mode. Also, the 33 band, and to a lesser degree, the 15 bands were more frequently affected by particle hits than the other three channels, thus resulting in the deletion of data in one or both when the other bands had data of good enough quality to be processed.

Duplicity_Flag
This flag parameter is set to 'D' to inndicate duplicity of the object, i.e., that at least two stars are present within 1 arcminute of the pointing position according to the Catalog of Stellar Identifications (CSI, see Ochsenbein et al., 1981A&AS...43..259O).

Variability_Flag
This flag parameter is set to 'V' to indicate variability. in the UV results as determined by tests described in Section 7.2.2 of the source reference paper.

Other_Notes
Other notes and remarks coded as follows:

      ? : duplicity and/or variability flag information uncertain;
      N : possible contribution from nebular emission;
      SL: spectral type probably later than listed;
      SE: spectral type probably earlier than listed;
      V?: suspected variable; for some of these objects the ground-based
          information may be erroneously listed in the source catalogs;
      E?: possible anomalous extinction (reddening) law;
      C : cluster star in crowded field, with possible UV data contamination;
      SD: possibly subluminous;
      D : stars listed as double in source other than CSI;
      D?: hot UV-bright companion probably present; may be a blue field star
           (field of view is 2.5x2.5arcminutes).
  

Class
The HEASARC Browse object classification based on the spectral type information.


Contact Person

Questions regarding the ANSUVPSCAT database table can be addressed to the HEASARC User Hotline.

Page Author: Browse Software Development Team
Last Modified: 16-Sep-2011