-----------------------------------------------------------
Introduction - Long-period variables (LPVs) are red giant stars that pulsate with periods from about a month to several years, and with amplitudes up to several magnitudes in the visual. All stars with masses up to about eight times the solar mass are predicted to become red giants after they have consumed hydrogen in their core (they then reach the so-called red giant branch, or RGB), and again after they have consumed helium in their core (they then reach the so-called asymptotic giant branch, or AGB).
They are very luminous, and hence detectable very far, beyond our Galaxy in extragalactic systems. Obeying period-luminosity relations, they are potential standard candles to measure distances in the Universe.
Figure 2. (W_RP, BP−RP − W_Ks,J−Ks ) vs. Ks diagram of Gaia DR2 LPVs in the Large Magellanic Cloud. The markers are colored with G_BP − G_RP according to the color-scale shown on the right of the figure. The solid line delineates O-rich (left of the line) and C-rich (right of the line) stars, and dashed lines delineate sub-groups as indicated in the figure. From Figure 1 of Lebzelter et al. (2018).
https://obswww.unige.ch/~mowlavi
Page updated 15/11/2018
-----------------------------------------------------------
Offline Website Builder