1098A I/98A NLTT Catalogue W J Luyten Minneapolis, University of Minnesota ??? ??? 1979 1979 W J Luyten H S Hughes Proper Motion Survey with the Forty-Eight inch Schmidt Telescope LV ??? ??? 1980 1980LP.....55....1L Proper motions The NLTT catalog is a collection of stars with proper motions exceeding 0.18"/yr found by Luyten and his coworkers. The First Supplement to the NLTT catalog is the result of continued plate analysis and contains data for 398 stars with proper motions greater than 0.179"/yr. A number of corrections to the data in the published catalog have been entered in the machine-readable version, including the omission of duplicate entries and those stars later determined to show no motion. The catalog contains, in addition to the proper motions, 1950 equatorial coordinates, a flag indicating the approximate accuracy of the positions, estimated red and photographic magnitudes, spectral types, and flags indicating a change from the published volume and the presence of the star in the supplement.

Name Star designation number=1 Identifiers without prefixes are DM (Bonner and Cordoba Durchmusterungen, written with a colon), or Luyten numbers from the Bruce Proper Motion Survey (L numbers) or the Luyten-Palomar Survey (LP numbers), the former in zones -45 to -89 deg and the latter in zones +89 to -44 deg. Other miscellaneous identifiers (Oxf = Oxford AC, Grw = Greenwich AC; U = Upgren; R = Ross, etc...). An asterisk (*) in the identification field indicates that a not exists in the "notes" file of the catalog. --- RAh Hours RA, equinox B1950.0 h RAm Minutes RA, equinox B1950.0 min RAs Seconds RA, equinox B1950.0 s RAm2 Right ascension, equinox B1950.0, minutes only min n_RAs Flag on RA: 1 = RA originally reported in 0.1min --- DE- Sign Dec, equinox B1950.0 --- DEd Degrees Dec, equinox B1950.0 deg DEm Minutes Dec, equinox B1950.0 arcmin Rmag Estimated red magnitude mag n_Rmag Flag on Rmag number=2 ':' indicates a larger uncertainty '+' indicates a mag fainter than reported value 'v' indicates a known variability --- Ptg Estimated photographic magnitude mag n_Ptg '+' Flag on Ptg number=2 ':' indicates a larger uncertainty '+' indicates a mag fainter than reported value 'v' indicates a known variability --- SpType Spectral type; lowercase letters represent estimated color classes or ranges. --- pm Relative proper motion, equinox B1950.0 number=3 The total proper motion is reported. The RA/DE proper motions can be computed with the formulae pmRA = pm.sin(pmPA) pmDE = pm.cos(pmPA) arcsec/yr u_pm ':' if proper motion is uncertain --- pmPA Position angle of PM vector number=3 The total proper motion is reported. The RA/DE proper motions can be computed with the formulae pmRA = pm.sin(pmPA) pmDE = pm.cos(pmPA) deg u_pmPA ':' if position angle is uncertain --- ModFlag 'A' indicates data have been changed (see Appendix A of adc.doc or adc.tex) --- SupplFlag '1' indicates a star from First Supplement (Luyten and Hughes, 1980) --- Name Star designation in one of many catalogs --- RAh Hours RA, equinox B1950.0 h RAm Minutes RA, equinox B1950.0 min RAs Seconds RA, equinox B1950.0 s DE- Sign Dec, equinox B1950.0 --- DEd Degrees Dec, equinox B1950.0 deg DEm Minutes Dec, equinox B1950.0 arcmin Text Note for star in free-form text --- adc.docDocumentation by Warren et al. (ascii) doc.texDocumentation by Warren et al. (LaTeX) Francois Ochsenbein CDS 1995Jun27 UNKNOWN UNKNOWN * A large number of corrections were performed at ADC, see section 3 of "adc.doc" or "doc.tex" files * From the "Selected Astronomical Catalogs" Vol. 1 CD-ROM (1992), directory /astrom/nltt * 30-Jun-1995: bad decimal point (blank or dashed) corrected in records 9694 (LP 198-153), column DEm 37692 (LP 381- 80), column pm 38236 (CD-68:1403), column Rmag 52719 (LP 983- 71), column DEm I_98A.xml