Cr 272 is a 13 Myr open cluster situated at a distance of 2300 pc from the Sun, close to the outer border of the inner arm -II. It is a spiral arm-tracer seen projected against a dusty region as it has been already stated by Fenkart et al. (1977). Indeed, further observation, e.g. polarimetry and spectroscopy, are needed to explain anomalous R-values. While the material in the direction to the cluster has a low chance of being responsible of this feature (which is confirmed by the normal reddening law in the neighbor cluster Hogg 16), we think that real star-to-star variations of R could be happening in the cluster itself.
Our analysis indicates that the cluster IMF is characterized by a
slope x =1.8 that, even at 
level, is still a bit far from
reconciliating a typical Salpeter slope. Concerning the membership
analysis (enterely based on photometric arguments), the reliability
of the slope of Cr 272 appears to be out of discussion due to the
conservative mass interval we have adopted to minimize incompleteness
effects. Although this slope could change (but not dramatically) if
another field star sample is considered,
we should recall, however, that only proper motion and radial velocity
studies can produce a more reliable result.
In view of the similar distances (
pc), proximity to each
other (
or 
pc), similar
reddening values (
) and the age difference (
Myr)
there is a chance for Cr 272 and Hogg 16 to be evolutionary linked.
This article is partially based on photographic data obtained using the UK Schmidt Telescope operated by the Royal Observatory Edinburgh. Original plate material is copyright the Royal Observatory Edinburgh and the Anglo-Australian Observatory. The plates were processed into the compressed digital form with their permission. The Digitized Sky Survey was produced at the Space Telescope Science Institute under US Government grant NAG W-2166.
Acknowledgements
The authors are indebted to Dr Garrison for the allocation of telescope time. R.A.V. thanks the generous collaboration of the Astronomical Institute of Bonn (Germany) staff during a scientific visit in 1992 granted by the Deutscher Akademischer Austauschdienst and the CONICET. We also acknowledge the comments and suggestions to improve this article made by Dr. J.-C. Mermilliod.