Recent observations of UGC4879 with the Advanced Camera for Surveys on the Hubble Space Telescope confirm that it is a nearby isolated dwarf irregular galaxy. We measure a distance of 1.36+/-0.03 Mpc using the Tip of the Red Giant Branch method. This distance puts UGC4879 beyond the radius of first turnaround of the Local Group and ~700 kpc from its nearest neighbor Leo A. This isolation makes this galaxy an ideal laboratory for studying pristine star formation uncomplicated by interactions with other galaxies. We present the star formation history of UGC4879 derived from simulated color-magnitude diagrams.
@article{arxiv.1010.1325,
title = {The Star Formation History of Isolated Dwarf UGC4879},
author = {Bradley A. Jacobs and R. Brent Tully and Luca Rizzi and Igor D. Karachentsev and Kristin Chiboucas and Enrico V. Held},
journal= {arXiv preprint arXiv:1010.1325},
year = {2011}
}
Comments
10 pages, 15 figures. Accepted for publication in the Astronomical Journal