Large Magellanic Cloud Distance Modulus Research Articles

The Extragalactic Distance Scale Key Project. IV. The Discovery of Cepheids and a New Distance to M100 Using the Hubble Space Telescope

view Abstract Citations (194) References (43) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The Extragalactic Distance Scale Key Project. IV. The Discovery of Cepheids and a New Distance to M100 Using the Hubble Space Telescope Ferrarese, Laura ; Freedman, Wendy L. ; Hill, Robert J. ; Saha, Abhijit ; Madore, Barry F. ; Kennicutt, Robert C., Jr. ; Stetson, Peter B. ; Ford, Holland C. ; Graham, John A. ; Hoessel, John G. ; Han, Mingsheng ; Huchra, John ; Hughes, Shaun M. ; Illingworth, Garth D. ; Kelson, Daniel ; Mould, Jeremy R. ; Phelps, Randy ; Silbermann, N. A. ; Sakai, Shoko ; Turner, Anne ; Harding, Paul ; Bresolin, Fabio Abstract We report on observations of Cepheids in the Virgo spiral galaxy M100, based on data obtained with the Wide Field and Planetary Camera 2 (WFPC2) on board the Hubble Space Telescope (HST). The observations are part of the HST Key Project on the Extragalactic Distance Scale, which aims to provide a measurement of the Hubble constant H_0_ with 10% accuracy. A total of 12 epochs were obtained using the F555W filter (transformed to Johnson V), and 4 epochs using the F814W filter (transformed to Cousins I). Photometry on the data was performed using two independent packages, DoPHOT and DAOPHOT II/ALLFRAME; a total of 52 Cepheids, with periods ranging from about 10 to 70 days, were identified based on both sets of photometry. We have fitted V and I period-luminosity relations and derived apparent V and I distance moduli assuming a Large Magellanic Cloud distance modulus and mean color excess of μ_LMC_ = 18.50 +/- 0.10 mag and E(B - V) = 0.10 mag, respectively. Using the extinction law given by Cardelli, Clayton, & Mathis, and adopting our most recent WFPC2 ("long- exposure ) zero-point calibration, we obtain a true distance modulus for M100 of μ_0_ = 30.04 +/- 0.17 mag, corresponding to a distance d = 16.1 +/- 1.3 Mpc, and a total (Galactic plus internal) mean color excess E(B - V) = 0.10 +/- 0.06 mag. When compared with the preliminary distance of 17.1 +/- 1.8 Mpc derived by Freedman et al. from the same set of data, the results presented here benefit from a larger sample size, refinements in the zero-point calibration, and improvements in the software packages used for the photometry. The two results agree to within their quoted errors. Publication: The Astrophysical Journal Pub Date: June 1996 DOI: 10.1086/177347 Bibcode: 1996ApJ...464..568F Keywords: STARS: CEPHEIDS; GALAXIES: DISTANCES AND REDSHIFTS; GALAXIES: INDIVIDUAL MESSIER NUMBER: M100 full text sources ADS | data products SIMBAD (98) NED (72) MAST (1) ESA (1) Related Materials (29) Part 1: 1994ApJ...427..628F Part 2: 1994ApJ...428..143H Part 3: 1996ApJ...463...26K Part 4: 1997ApJ...478..430K Part 6: 1997ApJ...475..853F Part 7: 1998ApJ...496..648H Part 8: 1996ApJ...470....1S Part 9: 1997ApJ...477..535G Part 10: 1997ApJ...490..517R Part 11: 1998ApJ...500..763P Part 12: 1998ApJ...501...32H Part 13: 1998ApJ...505..207T Part 14: 1998ApJ...507..655F Part 15: 1998ApJ...498..181K Part 16: 1999ApJ...515....1S Part 17: 1999ApJ...515...29M Part 18: 1999ApJ...512...48G Part 19: 1999ApJ...521..155M Part 20: 1999ApJ...514..614K Part 21: 1999ApJ...516..626G Part 22: 2000ApJ...528..655M Part 23: 1999ApJ...525...80P Part 24: 1999ApJ...523..540S Part 25: 2000ApJ...529..698S Part 26: 2000ApJ...529..723G Part 27: 2000ApJ...529..745F Part 28: 2000ApJ...529..768K Part 29: 2000ApJ...529..786M Part 30: 2000ApJ...545..547M

A color-magnitude diagram for the Large Magellanic Cloud cluster Hodge 11

view Abstract Citations (21) References (30) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS A Color-Magnitude Diagram for the Large Magellanic Cloud Cluster Hodge 11 Walker, Alistair R. Abstract A search for RR Lyrae variables in the vicinity of the old Large Magellanic Cloud (LMC) cluster Hodge 11 has resulted in the discovery of only one variable, which is probably a field star. A color-magnitude diagram (CMD) confirms that the cluster is very metal poor, [Fe/H]= -2.0+/-0.2, with E(V-I) = 0.10+/-0.02. The distribution of stars on the horizontal branch (HB) is skewed to the extent that only blue HB stars appear to be present-these have a bifurcated grouping, as in M 15. There are a few extremely blue stars that appear to be on a hotter extension of the HB- as they have no field counterparts these stars are likely cluster members. If the LMC distance modulus is assumed to be 18.5 mag, and a geometric correction corresponding to the position of Hodge 11 of -0.09 mag is applied, then M_v_(HB) = 0.44+/-0.12, in excellent agreement with that found for other old LMC clusters. The surrounding field population mostly has age 2-3 Gyr and [Fe/H]~-0.5- there is a significant break in the luminosity function at ~2 Gyr in that there are only a few younger stars. A small cluster near Hodge 11 has age ~1.5 Gyr. Publication: The Astronomical Journal Pub Date: September 1993 DOI: 10.1086/116699 Bibcode: 1993AJ....106..999W Keywords: Color-Magnitude Diagram; Magellanic Clouds; Star Clusters; Variable Stars; Metallicity; Star Distribution; Stellar Spectrophotometry; Astrophysics; MAGELLANIC CLOUDS; STARS: VARIABLES: RR LYRAE full text sources ADS | data products SIMBAD (23) NED (1) Related Materials (1) Erratum: 1994AJ....107.1204W