A CATALOGUE OF SPECTROSCOPICALLY IDENTIFIED WHITE DWARFS BY GEORGE P. McCOOK EDWARD M. SION JAN 1988 I. INTRODUCTION The first edition of this catalogue was published privately in May 1977(McCook and Sion 1977) as Villanova University Observatory Contributions No.2 and contained less than 500 degenerate stars.The preface to that edition provided a succinct rationale of our motivation for preparing the catalog and is presented here verbatim: "The number of newly discovered white dwarfs has increased substantially since the the appearance of the first comprehensive list by Eggen and Greenstein in 1965. The newly observed objects when added to the earlier lists comprise a sample approaching six hundred stars. New spectroscopic, spectrophotometric and photometric observa- tions are being obtained by several active groups throughout the world. The volume of data is enormous and much of it is dispersed throughout the literature. Some confusion exists with nomenclature especially regarding multiple names. The volume of data and the nature of its accessibility in the literature strongly suggested the need for a general comprehensive white dwarf catalogue. While there is clearly no substitute for using the primary reference literature, it may prove useful in certain applications for both observers and theoreticians to have the data collected into one catalogue. We apologize in advance for the inevitable errors in a catalogue of this size and welcome corrections and additions being brought to our attention for inclusion in possible future editions". Since the appearance of the First Edition of the Villanova Catalogue of Spectroscopically Identified White Dwarfs ,the number of newly identified spectroscopic degenerates has more than tripled due in a large part to the identification of several hundred new spectroscopic degenerates at the 5.1m Hale reflector by Jesse Greenstein and through the Palomar-Green North Galactic Pole survey of hot white dwarfs by R. Green, M. Schmidt, and J. Liebert. In addition, multi-channel spectrophotometry by Greenstein and Green is now available for over 500 white dwarfs while over 300 stars have Stromgren photometry due mostly to J.Graham ,G. Wegner, O. Eggen, M. Bessel, and D.T. Wickramasinghe. We decided in 1979 to postpone publication of the second edition until the large sample of hot white dwarfs discovered in the Palomar Green Survey became available for inclusion. In doing so ,the second edition(McCook and Sion 1984) presented a sample of nearly 1500 degenerate stars and a very much more complete compilation of color and parallax data for the proper motion selected sample. It was felt that the publication of the Villanova Catalogue of Spectroscopically Identified White Dwarfs, Third Edition, in the Astrophysical Journal Supplement would greatly increase its user accessibility and offer the opportunity to incorporate revisions, corrections and some additions to the second edition. The finalized Palomar-Green sample of degenerate stars (Green, Schmidt and Liebert, 1986) contained a number of revised object and spectral classifications resulting from extensive follow-up spectroscopy of the many objects having only single discovery spectra at lower resolution. As a result 30 Palomar-Green objects, misclassified as white dwarfs have been deleted from our catalogue, 16 Palomar-Green objects reclassified as degenerate stars have been added and 276 Palomar-Green stars were given revised spectral classifications. We have also added a large number of newly identified degenerate stars from the following sources: The Case Low Dispersion Northern Sky Survey (Sion, Wagner and Co-workers), the Kiso Ultraviolet Excess Survey (Wegner and Co-workers), the Kitt Peak Downes Survey (Downes and Co-workers), 5.1m Palomar CCD Spectroscopy by Greenstein, and Faint Spectroscopy of Luyten Palomar Proper Motion Stars by Hintzen. In addition, a number of new parallaxes and photometric colors have been added, the descriptions of the names entry have been expanded and the notes section has been significantly enlarged. II. SELECTION OF THE DATA, ENTRY CHANGES SINCE THE SECOND EDITION As in the First edition, we have attempted to include only white dwarfs with published spectroscopic identification. In a very few cases, colors and motions strongly indicate a white dwarf, but no spectral class has been as yet assigned. We have included white dwarfs that are components of essentially non-interacting binaries (eg. Roche lobe detached, short and long period systems) whose detected photospheric spectra are classifiable. A few examples illustrate the morphological range of such binary systems: HZ9, Sirius B, HZ43, the DA component of the mild Barium star Xi Ceti. We have attempted to include all data published or released to us in preprint form prior to January 1987. Based upon input we have received from colleagues, content changes have been introduced in the second edition which it is hoped will help to maximize the scientific usefulness of the second edition. A new white dwarf spectral classification system proposed by Sion, Greenstein, Landstreet, Liebert, Shipman, and Wegner (1983) has been implemented and is briefly described in the spectral class entry section below. An absolute visual magnitude has been computed for each star with measured colors or trigonometric parallax and the computational procedure is described in the entry section below. In addition, we have eliminated the equivalent width entries from the second edition and we have retained the observed radial velocity entry but eliminated the radial velocity corrected for solar motion and mean gravitational redshift. A seven digit WD number has been adopted and the notes section for white dwarfs of greatest astrophysical importance has been expanded. Names cross referenced with WD numbers have been expanded to include every white dwarf name used in the catalogue. The cross references are listed in appendix A. III. THE ENTRIES IN TABLE 2 All entries in table 2 except coordinates, names and absolute magnitudes are followed by a reference number in brackets e.g.(41). The reference list can then be used to identify the source of the catalogue entries. Column Heading WD The first entry contains a 'WD number', a catalogue number containing the first four digits of right ascension followed by the sign and the first two digits of declination and a third digit in which minutes of declination have been expressed as a fraction of a degree. Stars with identical catalogue numbers, whether binary or not, have been distinguished by using the designation .1 and .2 after their respective catalogue number. The same distinction is used for wide binary pairs. The choice of the 'WD number' format was made with the idea of continuing expansion of the catalogue as data accumulates. R.A. DEC The second entry contains the full right ascension and declination (1950.0) adopted according to the following order of priority: Lowell Observatory coordinates, United States Naval Observatory coordinates, Luyten Proper Motion Survey coordinates. For Bruce Proper Motion Survey stars, the coordinates may refer to epoch 1900.0 if no other proper motion name is listed. SP. CL. The third entry lists the spectral type according to the new system described by E.M. Sion, J.L Greenstein, J.D. Landstreet,J. Liebert, H.L. Shipman, and G.A. Wegner (1983) , where a complete discussion may be found. The system uses (1) an upper case D for degenerate; (2) an upper case letter for primary spectroscopic type in the optical spectrum; (3) an upper case letter for weaker or secondary spectroscopic features, if present, in any part of the electromagnetic spectrum and (4) a temperature index from 0 to 9 defined by 10 X i (i = 5040/T). Additional symbols to follow the second upper case letter are upper case P to indicate polarized magnetic stars, H for magnetic stars showing no detectable polarization, X for peculiar or unclassifiable spectra, and an optional V to denote the ZZ Ceti stars or any other variable degenerate star. Temperature-color index correlations using model atmospheres for DA and non-DA stars are available for multi- channel spectrophotometric colors (g-r); Stromgren colors (u-b, b-y); and broad band UBV colors (B-V, U-B). Temperatures derived from different model atmosphere grids are generally very consistent. We determine the temperature index by using the color transformations based upon tables 1 and 2 and equations (9) and (10) of Shipman (1979). The transformation relations for non-DA stars are (B-V) = 0.334 + 0.836 (g-r) and (b-y) = 0.286 + 0.553 (g-r). For DA stars, the color transformations are: (B-V) = 0.3336 + 0.5906 (g-r) and (b-y) = 0.2197 + 0.4485 (g-r). TABLE 1 ----------------------------------------------------------------- DEFINITION OF PRIMARY SPECTRAL SYMBOLS Spectral Type Characteristics DA Only Balmer lines: no HeI or metals present. DB HeI lines: no H or metals present. DC Continuous spectrum, no lines deeper then 5% in any part of the electromagnetic spectrum. DO HeII strong: HeI or H present. DZ Metal lines only: no H or He lines. DQ Carbon features, either atomic or molecular in any part of the electro- magnetic spectrum. * An asterisk indicates additional informa- tion in the Notes section, appendix A. b The letter "b" Indicates a binary member. ----------------------------------------------------------------- The definition of primary spectral symbols is given in table 1 according to the Sion et al (1983) classification.The primary symbols may be combined to designate atmospheres having hybrid compositions.For example a DB4 star showing CaII would be DBZ4,a DZ8 star with detectable H would be DZA8,a DO1 star with CIV(1550) would be DOZ1,et cetera.If more than one spectral class assignment has been made and cited and they are in agreement, the spectral type has been converted to the new system and is followed by the original reference(s). If more than one spectral class has been cited and they are in disagreement, a spectral type converted to the new system is given based upon our assessment of the spectral resolution and instrumental technology involved, but the old spectral types are retained followed by their references. In many cases the primary classification reference has not been listed but may be easily found in the secondary reference which is given. NAMES The fourth entry contains most of the names that exist for each star. The names are listed below with most of their references and an extensive cross reference, to the names used in Table 2, can be found in Appendix B. BPM Bruce Proper Motion Survey see reference list under Luyten C Case Stephenson, C.B. 1960,PASP, 72 ,387;1962,PASP, 74 ,610. CI20 Cincinnati Porter, J.G., Yowell,E.J., and Smith,E.S. 1930,Publ. Cincinnati obs.,No.20. CSO Case Low Dispersion Survey CBS Pesch, P., and Sanduleak, N. 1983,Ap.J.Suppl., 51 ,171 Sanduleak, N., and Pesch, P.1984,Ap.J. Suppl., 55 ,517. Pesch, P., and Sanduleak, N.1985,Ap.J.Suppl., 60 ,543. EG Eggen-Greenstein See reference list under Eggen and Greenstein. F Feige Feige, J. 1958,Ap.J., 128 ,267. G,GD,GH Lowell Names see reference list under Giclas GL Gliese Gliese, W. Von. 1957,Katalog der Sterne Naher als 20 parsek fur 1950.0, Heidelberg. GR Greenstein See reference list under Greenstein. GW Greenwich Astrographic Catalogue 1900.0 Greenwich Section,Vol.3 +64 to +90, F.W.Dyson,1914. HE Hertzprung Hertzsprung,E. 1918,A.N., 207 ,171. HL Tonantzintla Haro,G. and Luyten,W.J.1960,Bol. Obs. Tonantzintla y Tacubaya,No.29,16. HZ Humason-Zwicky Humason, M., and Zwicky, F. 1947,Ap.J., 105 ,85. K1 Kohoutek (K1-16) Perek, L., and Kohoutek, L. Catalogue of Galactic Planetary Nebulae 1967,Academia publ. house of the Czechoslovak Academy of Sciences, p.276,(Prague). Karpov (K1-12) Karpov, B.G. 1937,Pub.A.S.P., 49 ,146. KUV Kiso Kondo, M., Watanabe, E., Yutani, M., and Noguchi, T. 1982,Publ.Astron.Soc.Japan, 34 ,541. Noguchi, T., Maehara, H., and Kondo, M. 1980,Ann.Tokyo Astr.Obs.,Ser.2, 18 ,55. Kondo, M., Noguchi, T., and Maehara, H., 1984,Ann.Tokyo Astr.Obs.,Ser.2, 20 ,130. KPD Kitt Peak Downes Downes, R. 1986,Ap.J.Suppl. 61 ,569. L,LB,LP Luyten Names LDS,LHS,LTT see reference list under Luyten MK Markarian Markarian,B.E.,and Lipovetski,V.A. 1971, Astrofizika, 7 ,511. PB Palomar-Berger Berger, J., and Fringant, A. M. 1977,Astr.Ap.Suppl., 28 ,123 and subsequent papers. PG Palomar-Green Green, R.F., Schmidt, M., and Liebert, J.W. 1986,Ap.J.Supp., 61 ,305. PHL Tonantzintla Haro,G. and Luyten,W.J.1962,Bol. Obs. Tonantzintla y Tacubaya,3,No.22. R Ross Ross,F.E. 1925-1939,A.J., 36-48 . RB RWT Rubin Rubin, V.C., Westphal, D., and Tuve, M. 1974,A.J., 79 ,1406. SA Basle Halo Program Steppe,H.1978,Astr.Ap.Suppl., 31 ,209. SB Slettebak and Brundage Slettebak,A. and Brundage,R.K.1971,A.J., 76 ,338. TC Tonantzintla TON Iriarte, B., and Chavira, E. 1957,Bol.Obs. TPS Tonantzintla y Tacubaya,16,3. TS Chavira, E. 1958,Bol. Obs. Tonantzintla y Tacubaya,No.17. Chavira, E. 1959,Bol. Obs. Tonantzintla y Tacubaya,18,3. Philip,A.G.D. and Sanduleak,N.1968,Bol. Obs. Tonantzintla y Tacubaya,4,No.30. US Usher Usher, P. D. 1981,Ap.J.Suppl., 46 ,117 and subsequent papers. VB Van Biesbroeck Van Biesbroeck, G. 1961,A.J., 66 ,528. V Ma Van Maanen Van Maanen, A. 1938,Ap.J., 88 ,27. VR Van Rhijn-Raimond Van Rhijn, P.J. and Raimond, J.J. 1934,M.N.R.A.S., 94 ,508. W Wolf Wolf, M. 1919,Sternwarte zu Heidelberg,1,no.10, A.N., 209-236 ,1919-1929. Other Other Names--Refer to Fernandez,A.,Lortet,M.-C.,Spite,F. 1983,Astron.Astrophys.Suppl., 52 ,NO.4. WIDE BAND Entry five contains published values of wide band UBV V B-V U-B photometry. The V magnitude is listed followed by B-V, U-B and the reference number. If the star has not been observed on the UBV system, a photographic magnitude and color class (CC) is given from either the Lowell or Luyten Proper Motion Surveys. Photographic magnitudes are indicated by a PG following the magnitude in the V column. MC MC Entry six contains multi-channel spectrophotometric V g-r observations. The multi-channel V magnitude is listed followed by the multi-channel color and the reference. STROMGREN The seventh entry lists the Stromgren, narrow band, y b-y u-b photometry, y, b-y, u-b, and the reference. Mv The eighth entry lists the absolute visual magnitude computed from either trigonometric parallax or measured colors according to the following priority: (1) trigonometric parallax > 0".1 (2) multi-channel spectrophotometric colors (3) Stromgren narrow band colors and (4) UBV photometry. Exceptions to this priority system are denoted with numerical codes (0),(5), and (6) and are described below. If measured colors do not exist, an absolute magnitude was not given. For all spectral types with (g-r) color index the following calibration formula due to Greenstein (1984) was employed: Mv = 13.033 + 3.114 (g-r) -0.799 (g-r) 2 For all spectral types with (b-y) color index, the following calibration due to Green (1977) was adopted: Mv = 7.56 (b-y) + 11.50. The broad band calibrations are those of Sion and Liebert (1977). For DA white dwarfs with B-V < 0.4: Mv = 11.246 (B-V+1) 0.60 -0.045. For non-DA stars with B-V < 0.4: Mv = 11.916 (B-V+1) 0.44 -0.011. If B-V > 0.4 we used the following color-magnitude calibration due to Dahn et. al. (1982): Mv = (11.43q0.16)+(7.25q0.75)(B-V)-(3.42q0.68)(B-V) 2 In a few cases where 3 or more measured parallaxes from different sources are in agreement, exceptions were made to the priority system above. Likewise, for degenerate stars whose spectra exhibit abnormally strong or peculiar blanketing (e.g. G47-18, GD 229, LP701-29) and for very cool white dwarfs (e.g. LP131-66) the above priority system was not followed.Since for cool white dwarfs ,the blue colors(e.g.B-V,b-y,g-r) yield less accurate photometric parallaxes than the red colors(e.g.V-I,R-I),we have adopted absolute magnitudes from the recent tabulation of cool white dwarfs by Liebert,Dahn and Monet(1987) if our values differed by more than 0.3 magnitudes from theirs. These values are denoted by numerical code (6). An extensive tabulation of red colors of white dwarfs can be found in a review by Eggen(1985 and references therein) while V-I color indices are available from the USNO faint star parallax lists cited in this catalogue. Likewise for the very hot DA stars where the blue-sensitive color-magnitude calibrations are insensitive to temperature,we have used the values of M derived from actual effective temperature determinations as given for example,by Fleming et al.(1986) and Holberg et al.(1986).Here again however their values were adopted only if a discrepancy greater than 0.3 mag. existed. These values are denoted by numerical code (0). For the hottest helium-rich degenerates the photometric parallaxes are grossly inaccurate.For the DO and DOZ white dwarfs ,we have replaced the M value with the directly derivable effective temperature in units of 10 K. Most of the adopted values were from Wesemael et al.(1985) and are indicated by numerical code (5). A discussion of the dispersions and analysis of the above calibrations is given in Sion (1979) and Sion (1984). The value of absolute visual magnitude is followed by a number 1,2,3 or 4 to indicate the method of determination; (1) parallax; (2) multi-channel color; (3) Stromgren color and; (4) UBV color, or the value is followed by (0), (5) or (6) as described earlier. Stars with hybrid classifications were generally not assigned a photometric parallax. MU THETA The ninth entry contains the published values of proper motion and position angle followed by the reference. The units are seconds of arc per annum for proper motion, and degrees for the position angle. VR0 The tenth entry lists the observed radial velocity uncorrected for solar motion and gravitational redshift and followed by the reference. PI ME The final catalogue entry lists the published values of the trigonometric parallax in second of arc. In most cases the parallax is followed by the reported mean error in units of 0.001 seconds of arc. We are grateful to the many colleagues,too numerous to mention, who communicated data to us in advance of publication, and who sent to us, corrections and suggestions concerning the format and content of this edition. It is a pleasure to express our deepest gratitude to Drs. Jesse Greenstein and James Liebert for their valuable and detailed comments on this edition and to Dr. Hugh M. Van Horn at whose urging we decided to seek publication in a major journal instead of continuing to issue the catalogue privately. We thank William Harris,Kevin Hart,Brian McNamara, Robert Donahue, Scott Wacker, Raj Goyal, Matthew Lallo, and Joseph McMullin for their careful assistance with proofreading and data compilation. We gratefully acknowledge the support of the National Science Foundation through Grants AST78-13396-A01-A02 and AST85-17125 to Villanova University. References Dahn,C.C.,et.al. 1982,A.J. 87,426. Eggen,O.J. 1985,Pub.Astron.Soc.Pac. 97,1029. Fleming,T.,Green,R.F.,and Liebert,J. 1986,Ap.J. 308,176. Green,R.F. 1977,Ph.D. Thesis,Calif.Inst.Tech. Green,R F.,Schmidt,M.,and Liebert,J. 1986,Ap.J.Suppl. 61,305. Greenstein,J.L. 1984,Ap.J. 276,602. Holberg,J.B.,Wesemael,F.,and Basile,J. 1986,Ap.J. 306,629. Liebert,J.,Dahn,C.C.,and Monet,D.G. 1987,in preparation. McCook,G.P.,and Sion,E.M. 1977, A Catalogue of Spectroscopically Identified White Dwarfs,1st Edition,Villanova Univ. Obs. Contr. No.2. McCook,G.P. and Sion,E.M. 1977, A Catalogue of Spectroscopically Identified White Dwarfs,2nd Edition,Villanova Univ. Obs. Contr. No.3. Shipman,H.L. 1979,Ap.J. 228,240. Sion,E.M.,and Liebert,J. 1977,Ap.J. 213,468. Sion,E.M. 1979, IAU Colloq. No. 53, White Dwarfs and Variable Degenerate Stars, ed. H.M. Van Horn and V. Weidemann: Univ. of Rochester Press, p. 245. Sion,E.M.,Greenstein,J.L,Landstreet,J.D.,Liebert,J.,Shipman,H.L. and Wegner,G.A. 1983,Ap.J. 269,253. Sion,E.M. 1984,Ap.J. 282,612.. Wesemael,F.,Green,R.F.,and Liebert,J. 1985,Ap.J.Suppl. 58,379.