The Open UniversitySkip to content

First stellar spectroscopy in Leo P

Evans, C. J.; Castro, N.; Gonzalez, O. A.; Garcia, M.; Bastian, N.; Cioni, M.-R. L.; Clark, J. S.; Davies, B.; Ferguson, A. M. N.; Kamann, S.; Lennon, D. J.; Patrick, L. R.; Vink, J. S. and Weisz, D. R. (2019). First stellar spectroscopy in Leo P. Astronomy & Astrophysics, 622, article no. A129.

Full text available as:
PDF (Version of Record) - Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader
Download (7MB) | Preview
DOI (Digital Object Identifier) Link:
Google Scholar: Look up in Google Scholar


We present the first stellar spectroscopy in the low-luminosity (MV ∼ −9.3 mag), dwarf galaxy Leo P. Its significantly low oxygen abundance (3% solar) and relative proximity (∼1.6 Mpc) make it a unique galaxy in which to investigate the properties of massive stars with near-primordial compositions akin to those in the early Universe. From our VLT-MUSE spectroscopy we find the first direct evidence for an O-type star in the prominent H II region, providing an important test case to investigate the potential environmental dependence of the upper end of the initial mass function in the dwarf galaxy regime. We classify 14 further sources as massive stars (and 17 more as candidate massive stars), most likely B-type objects. From comparisons with published evolutionary models we argue that the absolute visual magnitudes of massive stars in very metal-poor systems such as Leo P and I Zw 18 may be fainter by ∼0.5 mag compared to Galactic stars. We also present spectroscopy of two carbon stars identified previously as candidate asymptotic-giant-branch stars. Two of three further candidate asymptotic-giant-branch stars display Ca II absorption, confirming them as cool, evolved stars; we also recover Ca II absorption in the stacked data of the next brightest 16 stars in the upper red giant branch. These discoveries will provide targets for future observations to investigate the physical properties of these objects and to calibrate evolutionary models of luminous stars at such low metallicity. The MUSE data also reveal two 100 pc-scale ring structures in Hα emission, with the H II region located on the northern edge of the southern ring. Lastly, we report serendipitous observations of 20 galaxies, with redshifts ranging from z = 0.39, to a close pair of star-forming galaxies at z = 2.5.

Item Type: Journal Item
Copyright Holders: 2019 ESO
ISSN: 1432-0746
Keywords: stars: early-type; stars: AGB and post-AGB; galaxies: individual: Leo P
Academic Unit/School: Faculty of Science, Technology, Engineering and Mathematics (STEM) > Physical Sciences
Faculty of Science, Technology, Engineering and Mathematics (STEM)
Item ID: 59301
Depositing User: ORO Import
Date Deposited: 26 Feb 2019 16:07
Last Modified: 30 Mar 2019 06:35
Share this page:


Altmetrics from Altmetric

Citations from Dimensions

Download history for this item

These details should be considered as only a guide to the number of downloads performed manually. Algorithmic methods have been applied in an attempt to remove automated downloads from the displayed statistics but no guarantee can be made as to the accuracy of the figures.

Actions (login may be required)

Policies | Disclaimer

© The Open University   contact the OU