On the Discrepancy between the Cepheid and RR Lyrae Distance Scales

Astronomy and Astrophysics – Astronomy

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

35

Cosmology: Distance Scale, Galaxies: Distances And Redshifts, Galaxies: Local Group, Stars: Abundances, Stars: Variables: Cepheids

Scientific paper

Available evidence suggests that there is a small discrepancy between distances to Local Group dwarf galaxies determined from Cepheids and RR Lyrae stars. This difference might be due to a slight metallicity dependence of the period luminosity relation for classical Cepheids. Such a dependence would have to be in the sense that metal-poor Cepheids of a given period are slightly fainter than their metal-rich counterparts. If this hypothesis is correct then recent Hubble Space Telescope distances to IC 4182 (SN 1937C) and NGC 5253 (SN 1972E) may have been slightly overestimated, resulting in a small increase in the Hubble parameter H0. Alternatively, the adopted relation between the metallicity and luminosity of RR Lyrae variables might be in error. It is noted that the rather faint Mv(RR) values observed in giant galaxies appear to conflict with the brighter values predicted by horizontal branch models.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

On the Discrepancy between the Cepheid and RR Lyrae Distance Scales does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with On the Discrepancy between the Cepheid and RR Lyrae Distance Scales, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and On the Discrepancy between the Cepheid and RR Lyrae Distance Scales will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1202469

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.