From fahlman@astro.ubc.ca Mon Aug 14 05:19:35 1995 Received: from kyohou.c.u-tokyo.ac.jp by chianti.c.u-tokyo.ac.jp (4.1/2.7W-utc1.9) id AA08290; Mon, 14 Aug 95 05:19:33 JST Received: from hub.ubc.ca by kyohou.c.u-tokyo.ac.jp (5.64/2.7W-utc1.9) id AA08947; Mon, 14 Aug 95 05:11:38 +0900 Return-Path: Received: from ubc.ca (wendigo.astro.ubc.ca [137.82.49.129]) by hub.ubc.ca (8.6.12/1.14) with SMTP id NAA03754 for ; Sun, 13 Aug 1995 13:13:44 -0700 Received: from lila.ubc.ca (lila.ARPA) by ubc.ca (4.1/1.14) id AA25203; Sun, 13 Aug 95 13:13:40 PDT Received: by lila.ubc.ca (5.0/SMI-SVR4) id AA10692; Sun, 13 Aug 1995 13:14:02 +0800 Date: Sun, 13 Aug 1995 13:14:02 +0800 From: fahlman@astro.ubc.ca (Greg Fahlman) Message-Id: <9508132014.AA10692@lila.ubc.ca> To: makino@chianti.c.u-tokyo.ac.jp Subject: IAU174 - abstract Content-Length: 1485 Status: R Dear Jun: I am enclosing a preliminary abstract for my talk at IAU174. I trust it will not be too late to be of use to you. Best wishes: Greg Fahlman. ------------------------------------------------------------------- New Observations of M4 with HST G.G. Fahlman. Univeristy of British Columbia A Canadian-American consortium has used the WFPC2 Camera on HST to obtain deep photometric observations in three radial fields of the nearby globular cluster M4. Recent progress with the analysis of this data will be described. The observations have clearly revealed an extensive white dwarf sequence whose locus in the cluster colour-magnitude diagram corresponds closely to the cooling sequence expected of 0.5 solar mass degenerate configurations. The observed cumulative luminosity function also agrees with the theory at least to the point where data incompleteness becomes important. The cluster main sequence is very well defined below our data saturation level and can be used to place limits on the fraction of nearly equal mass binaries among these stars. The apparent main sequence luminosity function shows a sharp break at an absolute visual magnitude of about 12. However, the data clearly shows that a sparsely populated main sequence continues to the limit of our data at V = 28. Therefore we have not yet reached the end of the hydrogen burning main sequence in this cluster. --------------------------------------------------------------------