The variability of GSC 6558-01290 = ASAS 075842-2536.1 was discovered by Pojmanski
(2002).
The ASAS-3 catalog lists the variable as an RRC star with the period of 0.41013 d.
I reinvestigated the star using the currently available ASAS-3 data and found it
an RR(B) star,
pulsating in the first and second overtone modes (an extension of the GCVS RR(B)
type,
which is defined as fundamental-mode and first-overtone pulsators).
The phased light curves plotted for the tabulated elements are shown in the Figure.
| Mode |
Frequency, c/d |
Semi-amplitude, V mag |
Period, day |
Epoch, HJD |
| f1 |
2.43827 |
0.158 |
0.410127 |
2453600.253 |
| f2 |
3.04768 |
0.033 |
0.328118 |
2453600.318 |
The period ratio P2/P1 = 0.8000 is typical of double-mode variables
pulsating
in the first and second overtone modes.
The tabulated coordinates of the variable were drawn from the
Tycho2 catalog. J–H = 0.231 (2MASS). The star is in a close pair
with the much fainter GSC 6558-00870; the combined brightness was measured, thus
the actual amplitude can be somewhat larger.
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