J/A+AS/137/305 IC 348 proper motion catalogue (Scholz+, 1999) ================================================================================ IC 348 proper motion study from digitised Schmidt plates. Scholz R.-D., Brunzendorf J., Ivanov G., Kharchenko N., Lasker B., Meusinger H., Preibisch T., Schilbach E., Zinnecker H. =1999A&AS..137..305S (SIMBAD/NED BibCode) ================================================================================ ADC_Keywords: Clusters, open ; Photometry ; Proper motions Keywords: astrometry - methods: statistical - open clusters and associations: individual: IC 348 - stars: kinematics Abstract: A new proper motion study for about 1400 stars with R<18mag in a one square degree region around the young open cluster IC 348 based on Schmidt plates is presented. With an overall accuracy of about 3mas/yr (2.5mas/yr, respectively for all stars with R<17mag) we have obtained membership probabilities dividing our sample into three groups: foreground stars, cluster stars and background stars. This separation is also supported by the proper motion distribution with respect to the direction of the standard antapex and an increase of mean proper motion cluster membership probabilities with smaller cluster radii. 240 stars of our sample have cluster membership probabilities larger than 80%. The results are compared with the highly accurate proper motion study of Fredrick (1956AJ.....61..437F) and with other catalogues (PPM, Cat. , ACT, Cat. , Hipparcos, Cat. ), all containing only bright stars. From PPM and ACT proper motions a cluster radius of about 30arcmin can be assumed. Hipparcos proper motions and parallaxes allow the separation of foreground stars, cluster stars and background stars in a somewhat larger region around IC 348 (with distances from the cluster centre of up to 85arcmin). On the basis of Hipparcos data we calculate a mean distance of 261_-23_^+27^pc for the cluster stars with common proper motion. This is nearly the same distance as obtained by de Zeeuw et al. (1999AJ....117..354D) for the Per OB 2 association covering more than 15 x 10 square degrees. The mean proper motion of the cluster IC 348 obtained in our study is in good agreement with that of the highly probable members of the Per OB 2 association according to de Zeeuw et al. (1999AJ....117..354D). Therefore, we conclude that the cluster IC 348 is embedded in the Per OB 2 association. From our proper motion membership probabilities we found a cluster radius of 10-15arcmin. There is a concentration of Fredrick's highly probable cluster stars just in between our cluster stars and the distant field stars proper motion distributions. On the other hand, two groups of stars in the proper motion diagram of Fredrick (1956AJ.....61..437F) also seem to be indicated if all his possible cluster members are considered. The X-ray sources from Preibisch et al. (1996A&A...310..456P) identified with optical counterparts from our proper motion sample show a strong concentration in the proper motion diagram. For these objects which are likely T Tauri stars we obtained high membership probabilities so that we conclude that they belong to the cluster IC 348 and to the Per OB 2 association. The proper motion foreground stars and cluster members which are counterparts of near-infrared (NIR) sources Lada & Lada (1995AJ....109.1682L) are located in different parts of the (J-H)-(H-K) two colour diagram, respectively. File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file catalog.dat 109 1431 IC 348 catalogue of proper motions -------------------------------------------------------------------------------- See also: I/239 : The Hipparcos and Tycho Catalogues (ESA 1997) I/246 : The ACT Reference Catalog (Urban+ 1997) I/146 : Positions and Proper Motions - North (Roeser+, 1988) Byte-by-byte Description of file: catalog.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 4 I4 --- Seq Sequential number (1) 6- 7 I2 h RAh Right ascension (J2000) (2) 9- 10 I2 min RAm Right ascension (J2000) 12- 16 F5.2 s RAs Right ascension (J2000) 18 A1 --- DE- Declination sign (J2000) 19- 20 I2 deg DEd Declination (J2000) 22- 23 I2 arcmin DEm Declination (J2000) 25- 28 F4.1 arcsec DEs Declination (J2000) 30- 36 F7.2 mas/yr pmRA Proper motion mu_alpha.cos(delta) 38- 44 F7.2 mas/yr pmDE Proper motion mu_delta 46- 50 F5.2 mas/yr e_pmRA rms uncertainty on pmRA 52- 56 F5.2 mas/yr e_pmDE rms uncertainty on pmDE 58- 62 F5.2 mag U9167 ?=99.99 U9167 magnitude 64- 68 F5.2 mag B9168 ?=99.99 B9168 magnitude 70- 74 F5.2 mag B9177 ?=99.99 B9177 magnitude 76- 80 F5.2 mag Bj ?=99.99 Bj magnitude 82- 86 F5.2 mag Vmag ?=99.99 V magnitude 88- 92 F5.2 mag Emag ?=99.99 E magnitude 94- 98 F5.2 mag Rmag ?=99.99 R magnitude 101-103 I3 % Pcl Membership probability of the cluster IC 348 106-108 I3 % Pdf Membership probability of the group of distant field stars -------------------------------------------------------------------------------- Note (1): Original number in a larger sample of all objects detected on the reference plate. Note (2): The coordinates are given for equinox J2000 but with the epoch of the reference plate e1457 (i.e. 1955.81). -------------------------------------------------------------------------------- Acknowledgements: Ralf Scholz ================================================================================ (End) Patricia Bauer [CDS] 16-Aug-1999