www.hnsky.org

An UCAC2 supplement for northern declinations  

(Makes the UCAC2 astrometric star catalog complete to +90 degrees declination)

The United States Naval Observatory is currently conducting an ongoing astrometric observation project. The second public release of data from this project is the UCAC2 catalog. The UCAC2 is a high density, highly accurate, astrometric catalog of 48,330,571 stars covering the sky from -90 to +40 degrees in declination and going up to +52 degrees in some areas.

The following files are UCAC2 supplements or extensions for declinations from +40 degrees up to +90 degrees. The USNO UCAC2 astrometric star catalog is not complete  for declinations above +40 degrees. The following supplement is an intermediate solution prepared by amateur astronomers using Tycho-2 and GSC_ACT data. This is a non-commercial initiative. All legal obligations/conditions/rules as described in the documentation of the original Tycho-2 catalogue are still valid and applicable.
 

In this UCAC2 supplement for Tycho only the Tycho-2 star position, Tycho-2 VT magnitude and adapted proper motion "pmra" (without cos(Dec)) and "pmde" are provided. All other fields are set at zero since the data is not always available and to keep these files very compressible.  The GSC_ACT version provides only star position and magnitude.
 

Any available UCAC2 stars above +40 degrees are abandoned in these supplements. All files should be placed in the UCAC2 directory e.g. \ucac2\u2  The original incomplete binary files from Z261 to Z288 and index file u2index.da have to be overridden.
 

ucac2sup.zip  New upload 2004-1-13, Version 2004-1-11. 441000 Tycho-2 stars, size  6.5 Mbytes including the original Tycho-2 readme.

Contains binary star files z261 to z360 and new index file u2index.da. Range +40.0 to +90.0 declination using Tycho-2 data.

 For already downloaded UCAC2 (Tycho-2) supplement versions dated before 11 January 2004 download this small updated index file  u2index.zip  

Download the UCAC2 supplement based on GSC_ACT, 45812150 stars, total 32.7 Mbytes:

ucac2_in.zip (new u2index.da for GSC_ACT extension),   ucac2_26.zip (z260..z269),   ucac2_27.zip (z270..z279),   ucac2_28.zip (z280..z289),   ucac2_29.zip (z290..z299),   ucac2_30.zip (z300..z309),  ucac2_31.zip (z310..z319),  ucac2_32.zip (z320..z329),  ucac2_33.zip (z330..z339),  ucac2_34.zip (z340..z349),  ucac2_35.zip (z350..z360)

Contains binary star files z261 to z360 and new index file u2index.da. Range +40.0 to +90.0 declination using GSC_ACT data.

Download also the latest HNSKY update

These supplements where created with the help of two amateur astronomers in Arizona. They and there computers worked very hard to sort the stars of the Tycho-2 and GSC_ACT catalogue in steps of 0.5 degrees in declination. The final binary conversion was done by Han Kleijn for use in his free HNSKY planetarium program www.hnsky.org or any other program. Please email any comments.

Clear skies, Han Kleijn 

• Back to the HNSKY software page.
• The final USNO UCAC2 catalogue is expected in 2005. Visit the official UCAC2 web page http://ad.usno.navy.mil/ucac/ .
• See also Instructions  and conversion programs to download and reconstruct the 2 Gbytes large USNO UCAC2 astrometric star catalog containing 48,330,571 stars from Vizier input files.
• Some screen shots using the UCAC2 in the HNSKY planetarium program.
• The Tycho-2 catalog information and links: http://www.astro.ku.dk/~erik/Tycho-2/   Catalog used I/259 The Tycho-2 Catalogue (Hog+ 2000), The Tycho-2 Catalogue of the 2.5 Million Brightest Stars Hog E., Fabricius C., Makarov V.V., Urban S., Corbin T., Wycoff G., Bastian U., Schwekendiek P., Wicenec A.

Counter:  Free counter

Last update  2004-1-16