================================================================================ Lick Northern Proper Motion Program: NPM1 Catalog (J2000 version) A.R. Klemola, R.B. Hanson, and B.F. Jones UCO/Lick Observatory, University of California Santa Cruz, CA 95064 USA June 2003 http://www.ucolick.org/~npm/NPM1/ ================================================================================ Reference: Klemola, A.R., Jones, B.F., and Hanson, R.B. (1987) Astronomical Journal 94, 501-515 ================================================================================ The NPM1 Catalog is the first part of the Lick Northern Proper Motion (NPM) program to measure absolute proper motions, on an inertial system defined by distant galaxies, for nearly 400,000 stars over a blue apparent magnitude range from 8 to 18. There are 1246 6-degree by 6-degree fields in the NPM survey (declinations +90 to -23 degrees). The 1993 NPM1 Catalog covers the 72% of the northern sky lying outside the Milky Way and contains some 149,000 stars from measures in 899 of the 1246 NPM fields. The 2003 NPM2 Catalog contains 232,000 stars in the 347 Milky Way fields, completing the Lick NPM program. The Yale Southern Proper Motion (SPM) program will eventually complete the southern sky. Each NPM field was photographed with the 51 cm Carnegie Double Astrograph at two epochs between 1947 and 1988. The mean first and second epochs are 1950 and 1977; the average epoch difference is 27 years. The first-epoch plates were taken in the blue only; both blue and yellow plates were taken at the second epoch. For NPM1, the plates were measured on the Automatic Measuring Engine (AME) at UC Santa Cruz. Some 50,000 faint reference galaxies were selected at the Lick Survey Machine, along with 94,000 stars chosen anonymously for the NPM astrometric reductions and for statistical studies of stellar motions, and 28,000 positional reference stars, and some 27,000 stars chosen for astronomical interest from Klemola's "Lick Input Catalog of Special Stars". The NPM1 Catalog, with positions, proper motions, and BV photographic photometry for 148,940 stars, was deposited with the data centers (ADC and CDS) in 1993 (I/199). The NPM1 Reference Galaxies were listed in a separate catalog (I/200), with positions and magnitudes only. The 1993 NPM1 Catalog is one data file (148,940 lines) concatenating the 114 one-degree declination zones from +89 degrees to -23 degrees. Each star has an NPM1 "name" reflecting the declination zone and a running number in right ascension order within the zone. Astrometric data are given in the B1950 coordinate frame, still in use at that time. The astrometric reference frame for the NPM1 positional reductions was the B1950 version of the ACRS catalog, so the NPM1 Catalog lists right ascensions and declinations for equinox B1950. For consistency in use, the positions were backdated from the original plate epochs (mean near 1968) to the catalog epoch 1950, using the NPM1 proper motions. The proper motions are on an absolute zero point determined by galaxies in each NPM1 field, but are on the B1950 system in the sense that their position angles are referred to the B1950 North Pole. For convenience to users, a J2000 version of the NPM1 Catalog was presented here in May 2000. In June 2003, after an overlap comparison with NPM2, we re-calculated the NPM1 transformation (B1950 to J2000) using an improved algorithm. The new version of NPM1 supersedes the version previously posted here. The NPM1 positions have been updated to the epoch 2000 using the NPM1 proper motions, and transformed into the J2000 coordinate system, following the procedures outlined by Lieske (A&A,73,282,1979) and by Aoki, et al. (A&A,128,263,1983). Transforming the NPM1 absolute proper motions into the J2000 system simply involves a small rotation to re-orient the position angle with respect to the J2000 Pole. Users should be aware that a hybrid catalog such as the B1950 NPM1 cannot be rigorously transformed to the J2000 system without a complete re-reduction of the plate measurements, starting in the J2000 frame, which we do not contemplate doing. However the new J2000 NPM1 is accurately on the J2000 coordinate system at the 0.1" level or better. The J2000 NPM1 Catalog is now given in the form of 114 separate files, one for each declination zone from +89 degrees (z+89j) to -23 degrees (z-23j). Within each zone, the stars are sorted in right ascension order. To avoid "renaming" stars, the B1950 NPM1 "names" were retained, but the user must note that these no longer strictly reflect the declination zone and right ascension order in the J2000 NPM1 Catalog. Each star's entry includes the J2000 position at epoch 2000, the NPM1 absolute proper motion oriented to the J2000 coordinates, and the blue (B) magnitude. For 97% of the stars the B-V color is also given. Other data given for each star are: the original mean epoch, a stellar class code, the number of NPM fields measured, and discrepancy flags for position, proper motion, and photometry. Finally, as an additional identification, the AGK3 (north) or SAO (south) number (if any) is given. The RMS precision of the NPM1 absolute proper motions is about 0.5"/cent (5 mas/yr) each coordinate. In each NPM1 field the proper motions were directly reduced to absolute, using an average of 60 galaxies per field. The RMS accuracy of the proper motion zero point in each field is about 0.2"/cent (2 mas/yr), consistent for stars over a wide magnitude range (12 < B < 18). Magnitude-dependent systematic errors, on the order of 1 mas/yr/mag, affect the brightest (8 < B < 12) NPM1 stars' proper motions. The RMS position errors at the new catalog epoch 2000 average about 0.2" (200 mas) in each coordinate, mostly due to the accumulated proper motion error from the original plate epochs to 2000. The pure positional errors at the original epochs (~1968) average 0.15" (150 mas) in each coordinate. The RMS errors for the NPM1 photographic photometry average about 0.2 mag in B, and 0.15 mag in B-V. More detailed information is available in the PostScript documentation for the 1993 (B1950) NPM1 Catalog (npm1.b1950.ps), written by R.B. Hanson. A full description of the goals, organizations,and methods of the Lick NPM program was given by Klemola, Jones, and Hanson (AJ,94,501,1987). We thank the National Science Foundation for its long-term support of the NPM program. NPM1 Catalog work was supported by NSF grant AST-9218084. Recent work was supported by NSF grant AST-9530632. Current work is supported by NSF grant AST-9988105. -------------------------------------------------------------------------------- Byte-by-byte Description of NPM1 declination zone file: -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 8 A8 --- Name [0-9.+-]! NPM1 star "name" made of: Byte 1 : Sign of B1950 declination for this zone Bytes 2-3: B1950 Declination zone Bytes 4-8: Running number in this B1950 declination zone 10- 11 I2 h RAh Right Ascension J2000 (hours) 13- 14 I2 min RAm Right Ascension J2000 (minutes) 16- 21 F6.3 s RAs Right Ascension J2000 (seconds) 23 A1 --- DE- Declination J2000 (sign) 24- 25 I2 deg DEd Declination J2000 (degrees) 27- 28 I2 arcmin DEm Declination J2000 (minutes) 30- 34 F5.2 arcsec DEs Declination J2000 (seconds) 35- 42 F8.2 arcsec/hyr pmRA Absolute proper motion RA (in "/century) 43- 50 F8.2 arcsec/hyr pmDE Absolute proper motion Dec. 51- 56 F6.2 mag B Photographic photometry (B magnitude) 57- 62 F6.2 mag B-V *?=-9.99 Photographic photometry (B - V color) 63- 68 F6.2 yr Epoch Original mean epoch of position (-1900) 69- 70 I2 --- class *[1,7] Code for class of star 71- 72 I2 --- nfields Number of NPM fields on which star was measured 74 I1 --- ips *Discrepancy flag Position 75 I1 --- ipm *Discrepancy flag Proper Motion 76 I1 --- ibv *Discrepancy flag Photometry 77- 83 I7 --- icatno *AGK3 and SAO identification 84 A1 --- agksgn *AGK catalog identification -------------------------------------------------------------------------------- Note on B-V: (= -9.99 if no data) Note on class: The code is a sum of the following numbers, if applicable. +1 if anonymous star (faint or bright) +2 if catalog star (AGK3 or SAO) +4 if other star (Lick Input Catalog) Note on ips, ipm and ibv: As defined in Table 2 of the Document file (npm1.txt) ---------------------------------------------------- Position Proper Motion Photometry ---------------------------------------------------- Flag=0 O.K. O.K. O.K. Flag=1 R.A. R.A. B Flag=2 Dec. Dec. B - V Flag=3 Both Both Both Flag=9 Error Error Error ---------------------------------------------------- Limits 1.0 arcsec 3.0 arcsec/cent 1.0 mag Note on icatno: AGK3 identification for zones +89 to -01 SAO identification for zones -02 to -23 Note on agksgn: blank if AGK zone = NPM zone + if AGK zone = NPM zone + 1 - if AGK zone = NPM zone - 1 ================================================================================ Robert B. Hanson 2000 May 30; revised 2003 June 6.