An analogy is to consider the human population in a large school complex offering classes from kindergarten to 12th grade, where even a brief study would be sufficent for a trained scientist to fully characterize the development of the human species from early childhood through to adulthood.
This week's image presents NGC2099, also known as Messier 37, a rich open cluster located about 5000 light years away, in the constellation Auriga.
This two-color picture of NGC2099 was created from separate five minute exposures at blue and yellow wavelengths using the CFHT12K camera at the Canada-France-Hawaii Telescope.
SCYON: Paper abstracts(Site not responding. Last check: 2007-10-15)
The CCD observations of the rich open star cluster NGC2099 and its surrounding field region have been carried out up to a limiting magnitude of V about 22 mag in B, V and I passbands for the first time.
A total of about 12000 stars have been observed in the area of about 24 arcmin X 34 arcmin in the cluster region, as well as about 2180 stars in the 12 arcmin X 12 arcmin area of the field region located about 45 arcmin away from the cluster center.
It becomes closer to the Salpeter value of -1.35, if flattening in the cluster mass function due to presence of both binaries and a much more extended corona is considered.
[No title](Site not responding. Last check: 2007-10-15)
This is particularly important in the case of NGC2099 as the age is similar to that of the Hyades cluster, for which current models have difficulties in reproducing the details of the main-sequence turnoff.
We also derive the reddening [E(B-V)=0.21+/-0.03] and distance [(m-M)V=11.55+/-0.13] to NGC2099 by matching main-sequence features in the cluster to a new fiducial main sequence for the Hyades, after correcting for small metallicity differences.
We find some evidence for mass segregation within the boundary of NGC2099 as expected given the cluster's age relative to the dynamical age.
In the same field of view you may also see a dimmer open cluster, NGC 1907, a magnitude 8.2 object, but you won't be deceived, M38 is easily visible.
Our third and final Messier object in Auriga, is the 5.6 magnitude open cluster M37, NGC2099.
M37 is about 4 degrees south-east of M36 and forms the apex of the left leg of a equilateral triangle formed with M36 at the top and the star Elnath at the apex of the right leg of the triangle.
An Adaptive Optics Survey of OB Stars in the NGC 6611 Cluster.
Hibbard, J. E.; van der Hulst, J. Barnes, J. ; Rich, R. High-Resolution H I Mapping of NGC 4038/39 ("The Antennae") and Its Tidal Dwarf Galaxy Candidates.
Liu, M. ; Graham, J. Infrared Surface Brightness Fluctuations of the Coma Elliptical Galaxy NGC 4874 and the Value of the Hubble Constant.
Precise (1" or better) positions have been determined or verified for all the planetary nebulae appearing the NGC and IC catalogues.
Despite publication in 1990 of the "Strasbourg-ESO Catalogue of Planetary Nebulae", many of the objects there are given with either imprecise or simply incorrect coordinates.
The best published position for the open cluster (also NGC 2818) is in the ESO/Uppsala Survey of the ESO (B) Atlas, first listed by Holmberg et al.
J/A+A/307/80 Velocities of red giants in NGC2099 (Mermilliod+ 1996) ================================================================================ Red giants in open clusters: V. Mermilliod J.-C., Huestamendia G., del Rio G., Mayor M.
NGC 3680 and IC 4651 (Mermilliod+ 1995) J/A+A/319/481 : Part VI.
Note (1): The numbering system used for NGC2099 is from: von Zeipel H., Lindgren J. 1921, Kungl.Sven.Vet.Handl.
The CFHT Open Cluster Survey : NGC 2099(Site not responding. Last check: 2007-10-15)
Figure 1 : True-color portrait of the rich open star cluster NGC2099, located at about 5000 light-years from the Sun, and containing over 2000 stellar members.
Figure 3 : This diagram (called a color-magnitude diagram, or CMD) shows the brightnesses of the stars in NGC2099 plotted against their colors.
The left-hand panel shows the existing data obtained with photographic plates in 1967 by West while the right-hand plot exhibits the new data just recently obtained with the large mosaic imager on the Canada-France-Hawaii Telescope.
[79.02] The White Dwarf Cooling Age of the Rich Open Star Cluster NGC 2099 (M37)(Site not responding. Last check: 2007-10-15)
For the case of the intermediate aged cluster NGC2099 (M37), our photometry is faint enough to accurately detect the remnants of the most massive progenitor cluster stars under the Type I Sne limit.
Therefore, the CMD of the cluster exhibits a well defined white dwarf `clump' caused by the decreased rate of cooling of these stars as they age.
Furthermore, after carefully accounting for uncertainties in the ages, we can rule out a non core-overshooting model of age 300-350 Myrs for the cluster.
Publications Group, SAO 2000 Bibliography(Site not responding. Last check: 2007-10-15)
A., Pérez-Fournon, I., Argon, A. L., and Moran, J. "The Active Jet in NGC 4258 and Its Associated Shocks." Astrophysical Journal 536 (2000): 675.
R., and Schachter, J. "HRI Observations of PMS Stars in NGC 2264." Astronomy and Astrophysics 355 (2000): 651.
R., and Schachter, J. "An HRI Survey of NGC 2264: Properties of X-Ray Emission and IMF Determination." In Stellar Clusters and Associations: Convection, Rotation, and Dynamos, ASP Conference Series, vol.
