Release History for the on-line SuperCOSMOS Sky Survey

• July 14th 2006: Final release of the full-blown SSS after inclusion of the POSS-II I and northern POSS-I E data. Note that at the North Celestial Pole there is no covering field number 898 in the I band (field numbers 895 to 897 are present, and match the same fields in Bj and R).
• September 27th 2004: Final release of POSS-II Bj and R data in the northern hemisphere. All POSS-II Bj and R glass copies have now been scanned and placed online with the exception of fields 823 to 894 (the equatorial strip) which is covered by the southern UKST surveys. Note also that field 1 does not exist in POSS-II; rather there are four non-ESO/SRC reflected fields at numbers 895 to 898, taken 4hr apart at Dec=+89, that cover the NCP. The photometric calibration of the entire northern Bj and R surveys has been rederived, so existing calibrations will have changed at a very low level.
• May 12th 2004: First release of POSS-II Bj and R data in the northern hemisphere. 563 fields out of 822 (68%) of the northern sky at higher Galactic latitudes are now online. The drop-down menus in the pixel and object catalogue web forms now include options to select POSS-II Bj or R data.
• April 23rd 2004: The new SuperCOSMOS Science Archive is now available. For fully flexible querying of object catalogue data and other features, use that facility rather than the standard SSS web forms.
• June 5th 2003: Proper motion measurements now incorporate all plate measurements where available (ie. proper motions are no longer based on just UKJ and UKR). This results in much higher accuracy in the equatorial zone (-20 < Dec < +2.5) where the UKJ/UKR epoch differences are generally small, and newly incorporated POSS-I E measures (epoch 1949 to 1958) yield a much larger time baseline. Note that when only a limited epoch range is available (eg. for UKI/UKR-only pairs in field 862) very large proper motions and proper motion errors occur. Before using SSS proper motions, the significance of the mesurement should always be checked using the corresponding error estimate (eg. only use if pm > 5x sigma_pm)
• May 22nd 2003: Final release of the SSS, with field UKI001 now populated (best plate available at that time).
• December 3rd 2002: UKI, ESOR and PAE surveys have been updated: sky coverage is now complete except for one UKI field (ESO/SRC field 1 at the South Celestial Pole). All photometric zeropoints in the UKI, ESOR and PAE surveys have been updated, so previously existing zeropoints will have changed slightly (especially in fields adjacent to new data). The access software has been modified so that in the equatorial region (-20 < Dec < 0), PAE data are paired into four-colour datasets to provide "R1" data in the region not covered by the ESO-R survey.
• August 23rd 2002: small bug fixed in object catalogue access codes (this bug sometimes resulted in missing data when catalogue queries traversed field boundaries, especially in low latitude regions).
• March 2002: new release of SSS data. Database is now 97% complete in UKI, 75% complete in ESOR (UKJ and UKR are 100% complete from previous release and are unchanged at this release). Additional POSS-I E fields added in the SDSS EDR regions.
• July 2001: new release of SSS data. UKI fields 21 & 165 replaced; UKR fields 52, 54, 632 & 647 replaced. Field 83 pairing bugs fixed. Many new ESOR and UKI fields added (UKI is now 60% complete) so photometric zeropoints in these colours have changed significantly.
• May 2001: old SSS server has been replaced by new server plus RAID disk system. J and R southern hemisphere surveys are now complete; new ESO-R and I data are available outwith the SGC region. ALL photometric zeropoints have been rederived; ALL astrometry has been rereduced wrt Tycho-2; consequently all photometric and astrometric data will have changed slightly. Enhanced user options now include new photometry and pairing options. For detailed information see the three survey papers (available under Documentation).
• October 2000: R/I photometric calibration changed to account for systematic errors in colour as a function of position and magnitude. The corrections have been done with respect to the J magnitudes, which have not changed (ie. J-R and J-I colours are now self-consistent and anchored at the same median value across the entire survey).
• 4/5/6 July 2000 New data added in for 21 UKR film and 2 further UKR glass originals. UKR photometric zeropoints have been rederived; exisiting field zeropoints have changed by between 1% and 10%. Proper motion data has been derived for the 23 new fields.
• 2 May 2000 FITS WCS keyword set modified to follow the most recent draft definition (Greisen & Calabretta 1999; CD rotation matrix). All previous keywords are STILL INCLUDED. If your software has problems understanding these FITS WCS keywords, PLEASE GET IN TOUCH WITH US.
• 11 Jan 2000 Small bug fixed in database access software which lead to unpaired objects having spurious proper motions instead of null values.
• 23 Nov 1999 Proper motion information added in for all 171 fields having first epoch J and second epoch R.
• 19 Nov 1999 Three new second epoch red fields added to the database (151, 158 and 200).
• 11 Nov 1999 All photometric zeropoints have been rederived (many fields have changed only at the 0.01mag level, but some have changed by several tenths)
• 22 Oct 1999 ESOR data for fields 197, 417 and 538 reinstalled to fix a pixel glitch affecting one lane in each.
• 25 Sep 1999 Galaxy photometry calibration finalised
• 02 Sep 1999 Small bug in pairing repaired (only affecting parent objects)
• 06 Aug 1999 Object catalogue access set up (beta release)
• 04 Aug 1999 New pixel access software installed (enhanced FITS tables including colours)
• 08 Jul 1999 First stable version of beta-release
• 01 Jun 1999 Data online and web server set up