Osservazioni e curve di luce
Sessione del 18 luglio 2007
- Osservatorio Astronomico di Nova Milanese
-
Minor Planet Center, codice"A25" - American Association
of Variable Stars Observers, codice "BVN" - Codice GRAV "BMA"
Observer: Massimo Banfi
AR Her
| AR | Dec | Mag. | Tipo | Ref | Mv(Ref) | Check | Cartina |
|---|---|---|---|---|---|---|---|
16 00 32
|
46 55 26 |
10.59 - 11.63 |
RRab |
GSC 3491 320 |
10.77 |
GSC 3491-80 |
Periodo: 0.470028
RR variables are stars of the RR Lyrae type, which are radially-pulsating giant A-F stars having amplitudes from 0.2 to 2 mag in V. Cases of variable light-curve shapes as well as variable periods are known. If these changes are periodic, they are called the "Blazhko effect."
Traditionally, RR Lyrae stars are sometimes called short-period Cepheids or cluster-type variables. The majority of these stars belong to the spherical component of the Galaxy; they are present, sometimes in large numbers, in some globular clusters, where they are known as pulsating horizontal-branch stars. Like Cepheids, maximum expansion velocities of surface layers for these stars practically coincide with maximum light.
RRAB variables are RR Lyrae variables with asymmetric light curves (steep ascending branches), periods from 0.3 to 1.2 days, and amplitudes from 0.5 to 2 mag in V.
Osservazioni e curve di luce
Sessione del 18 luglio 2007
Sessione del 27 giugno 2007
Sessione del 24 giugno 2007
Sessione di tre ore del 24 maggio, disturbata da una forte foschia e dal chiarore lunare.
Sessione di circa tre ore del 22 maggio 2007.
