Distances within Local Group
Distance to the M31: 740 +/- 40 kpc
Its distance is always referred to the LMC,
because this provides the zero-point calibration.
Comparison of cepheids in LMC and M31 show that the latter lies 15.3 +/-
0.8 times farther away. Comparison of RR Lyraes give a distance ratio of
15 +/- 1.
The PN luminosity function also provides a distance ratio wrt LMC of 15 +/-
1 kpc.
The peak in the GCLF can be compared to that of the Milky Way, and the distance
derived in this way is 700 +/- 60 kpc. This is directly calibrated wrt Milky
rather than the LMC. The fact that there is such good agreement between different
estimators and zero-points gives good confidence that the scale is correct.
Novae
|
710 +/- 80 kpc
|
RR Lyrae
|
750 +/- 50 kpc
|
Cepheids
|
760 +/- 50 kpc
|
PNLF
|
750 +/- 50 kpc
|
GCLF
|
700 +/- 60 kpc
|