• Home
  • A uvbyCaHβ CCD Analysis of the Open Cluster Standard NGC 752

A uvbyCaHβ CCD Analysis of the Open Cluster Standard NGC 752

Precision uvbyCaHβ photometry of the nearby old open cluster, NGC 752, is presented. The mosaic of CCD fields covers an area ˜42‧ on a side with internal precision at the 0.005-0.010 mag level for the majority of stars down to V ˜ 15. The CCD photometry is tied to the standard system using an extensive set of published photoelectric observations adopted as secondary standards within the cluster. Multicolor indices are used to eliminate as nonmembers a large fraction of the low probability proper-motion members near the faint end of the main sequence, while identifying 24 potential dwarf members between V = 15.0 and 16.5, eight of which have been noted before from Vilnius photometry. From 68 highly probable F dwarf members, we derive a reddening estimate of E(b - y) = 0.025 ± 0.003 (E(B - V) = 0.034 ± 0.004), where the error includes the internal photometric uncertainty and the systematic error arising from the choice of the standard (b - y, Hβ) relation. With reddening fixed, [Fe/H] is derived from the F dwarf members using both m1 and hk, leading to [Fe/H] = -0.071 ± 0.014 (sem) and -0.017 ± 0.008 (sem), respectively. Taking the internal precision and possible systematics in the standard relations into account, [Fe/H] for NGC 752 becomes -0.03 ± 0.02. With the reddening and metallicity defined, we use the Victoria-Regina isochrones on the Strömgren system and find an excellent match for (m - M) = 8.30 ± 0.05 and an age of 1.45 ± 0.05 Gyr at the appropriate metallicity.

Astronomical Journal, 150, 134, 2015

File: 
Authors: 
Twarog*, Bruce A.; Anthony-Twarog*, Barbara J.; Deliyannis, Constantine P.; Thomas*, David T. * KU Authors

Department Communications

Colloquia         Seminars         Public Events         AAL

MARAC2018

NEWSLETTERS

Department            Alumni

VIDEOS

Mr. Bob Show              Colloquia

Alumni Remembrances          Public Lectures

Departmental Calendar

Mr. Bob T-Shirts: Lab Support
Home to 50+ departments, centers, and programs, the School of the Arts, and the School of Public Affairs and Administration
KU offers courses in 40 languages
No. 1 ranking in city management and urban policy —U.S. News and World Report
One of 34 U.S. public institutions in the prestigious Association of American Universities
44 nationally ranked graduate programs.
—U.S. News & World Report
KU Today
It may turn out that the key to beating back an unconquerable foe, antibiotic resistance, is an invented protein in… https://t.co/portQeNxBm


Social Media

Find us on Facebook