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J/ApJ/617/L41   Red giant variable candidates in UMi dSph       (Mighell+, 2004)

Flickering red giants in the Ursa minor dwarf spheroidal galaxy: detection of low-amplitude variability in faint red giant branch stars on 10 minute timescales. Mighell K.J., Roederer I.U. <Astrophys. J., 617, L41-L44 (2004)> =2004ApJ...617L..41M
ADC_Keywords: Stars, variable ; Stars, giant ; Photometry Keywords: galaxies: individual (Ursa Minor dwarf spheroidal) - methods: statistical - stars: variables: other - techniques: photometric Abstract: We have analyzed two epochs of Hubble Space Telescope Wide Field Planetary Camera 2 observations of the Ursa Minor dwarf spheroidal galaxy using the HSTphot photometric reduction package. We report the detection of nine faint (MV≳0.0mag) red giant variable stars that exhibit low-amplitude brightness fluctuations on 10 minute timescales with amplitudes ranging from 36 to 130mmag. Description: Two sets of HST WFPC2 observations of the UMi dSph were used in this investigation. The first set of observations (u2pb0101t to u2pb0106t), from the program GTO-6282 (PI: Westphal), was obtained on 1995 July 4 and included three images (each ≤1100s) through the F555W (∼V) filter and three images (each ≤1200s) through the F814W (∼I) filters. The second set of observations (u5er1301r to u5er1308r), from the program GO-8095 (PI: Ibata), was obtained nearly 4 years later on 1999 July 2 and included four images (each ≤500s) in F555W and four images (each ≤500s) in F814W. Objects: ---------------------------------------------------------- RA (2000) DE Designation(s) ---------------------------------------------------------- 15 09 11.3 +67 12 52 UMi dSph = UGC 9749 15 08 33.33 +67 12 15.6 HST dataset u2pb0101t 15 08 33.34 +67 12 14.7 HST dataset u5er1301r ---------------------------------------------------------- File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 175 18 Photometry of the RGB variable candidates
See also: J/AJ/90/2221 : UMi dwarf galaxy BV photometry (Olszewski+, 1985) Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 4 A4 --- Name RGB variable candidate identification 6- 14 I9 --- ID Location identification code (1) 16- 19 I4 yr Epoch Epoch of observation 21- 25 F5.3 mag AV Amplitude in V band (2) 27- 32 F6.3 mag <Vmag> Mean V magnitude (F555W filter) 34- 39 F6.3 mag Vmag1 Vmag1 (F555W filter) 41- 46 F6.3 mag Vmag2 Vmag2 (F555W filter) 48- 53 F6.3 mag Vmag3 Vmag3 (F555W filter) 55- 60 F6.3 mag Vmag4 ?=99.999 Vmag4 (F555W filter) 62- 66 F5.2 --- Vchi2 Chi squared in V band 68- 72 F5.3 mag e_<Vmag> Error in <Vmag> 74- 78 F5.3 mag e_Vmag1 Error in Vmag1 80- 84 F5.3 mag e_Vmag2 Error in Vmag2 86- 90 F5.3 mag e_Vmag3 Error in Vmag3 92- 97 F6.3 mag e_Vmag4 ?=99.999 Error in Vmag4 99-103 F5.3 mag AI Amplitude in I band (2) 105-110 F6.3 mag <Imag> Mean I magnitude (F814W filter) 112-117 F6.3 mag Imag1 Imag1 (F814W filter) 119-124 F6.3 mag Imag2 Imag2 (F814W filter) 126-131 F6.3 mag Imag3 Imag3 (F814W filter) 133-138 F6.3 mag Imag4 ?=99.999 Imag4 (F814W filter) 140-144 F5.2 --- Ichi2 Chi squared in I band 146-150 F5.3 mag e_<Imag> Error in <Imag> 152-156 F5.3 mag e_Imag1 Error in Imag1 158-162 F5.3 mag e_Imag2 Error in Imag2 164-168 F5.3 mag e_Imag3 Error in Imag3 170-175 F6.3 mag e_Imag4 ?=99.999 Error in Imag4
Note (1): The leftmost digit of the identification gives the WFPC2 CCD number (1, 2, 3, or 4, for cameras PC1, WF2, WF3, or WF4, respectively) where the star was found in the first F555W observation of each epoch of observation (1995: u2pb0101t; 1999: u5er1301r). The rightmost four digits give the x-coordinate of the star multiplied by 10. The remaining four digits give the y-coordinate of the star multiplied by 10. For example, the first star has an ID of 173764892, indicating that it is found on the PC1 image at the (x,y) location of (489.2,737.6). Note (2): The amplitudes AV and AI are defined as being the difference between the faintest and the brightest magnitude measurements for V and I respectively.
History: From electronic version of the journal
(End) Greg Schwarz [AAS], Marianne Brouty [CDS] 17-Jun-2005
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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