In the wings of a foreground star that is five magnitudes brighter. In R in particular daophot struggles to make any fit.
MJD | V | * | Image | B | * | Image | R | * | Images | I | * | Images |
---|---|---|---|---|---|---|---|---|---|---|---|---|
56142.34 | >15.870 | - | -- | - | - | -- | - | - | -- | - | - | |
56267.16 | -- | - | - | -- | - | - | 18.23± 0.05 | - | -- | - | - | |
56537.17 | 19.52± 0.14 | T | > 16.76 | - | 18.32± 0.06 | - | -- | - | - | |||
56930.14 | 19.37± 0.12 | T | > 16.71 | - | 18.26± 0.06 | - | -- | - | - | |||
57285.24 | 19.47± 0.10 | T | > 17.16 | - | 18.23± 0.06 | - | -- | - | - | |||
57340.19 | >17.140 | - | -- | - | - | -- | - | - | 19.28± 0.29 | T | ||
57633.38 | >17.080 | - | > 17.43 | - | 18.43± 0.06 | - | -- | - | - | |||
57635.27 | 19.35± 0.11 | - | 19.90± 0.12 | - | 18.27± 0.06 | - | 18.33± 0.09 | - | ||||
57659.15 | 19.84± 0.18 | - | -- | - | - | -- | - | - | 18.71± 0.16 | - | ||
57687.09 | 19.27± 0.09 | - | > 17.23 | - | 18.42± 0.07 | - | 18.34± 0.12 | - | ||||
57958.40 | 19.25± 0.09 | T | -- | - | - | -- | - | - | > 15.30 | - | ||
57963.41 | 19.45± 0.10 | - | > 15.56 | - | 18.37± 0.07 | - | -- | - | - | |||
57988.26 | 19.52± 0.09 | - | 19.94± 0.14 | - | 18.31± 0.06 | - | -- | - | - | |||
58067.16 | 19.89± 0.12 | - | -- | - | - | -- | - | - | 18.77± 0.11 | - | ||
58098.14 | 19.70± 0.10 | - | 19.86± 0.11 | - | -- | - | - | -- | - | - | ||
58317.28 | 19.63± 0.14 | - | 20.09± 0.18 | - | 18.47± 0.07 | - | -- | - | - | |||
58339.27 | 19.93± 0.12 | - | -- | - | - | -- | - | - | 18.78± 0.13 | - | ||
58342.27 | 19.77± 0.15 | T | 20.06± 0.18 | - | -- | - | - | -- | - | - | ||
58373.09 | >16.640 | - | > 16.36 | - | -- | - | - | -- | - | - | ||
58671.35 | 19.48± 0.12 | A | 20.19± 0.15 | - | 18.39± 0.06 | - | -- | - | - | |||
58673.32 | 19.75± 0.08 | - | 20.36± 0.13 | - | -- | - | - | -- | - | - | ||
58750.16 | 19.53± 0.07 | - | -- | - | - | 18.48± 0.05 | - | 18.63± 0.11 | - | |||
58784.10 | 19.79± 0.07 | - | 20.15± 0.10 | - | -- | - | - | -- | - | - | ||
58836.15 | >16.790 | - | -- | - | - | 18.54± 0.08 | T | 18.79± 0.12 | T | |||
59026.38 | 19.70± 0.09 | - | > 15.37 | - | 18.48± 0.06 | - | -- | - | - | |||
59056.27 | 19.79± 0.12 | - | 19.87± 0.11 | - | -- | - | - | 18.81± 0.12 | - | |||
59077.27 | 19.75± 0.09 | - | -- | - | - | 18.43± 0.06 | - | 18.59± 0.09 | - | |||
59082.24 | 19.76± 0.11 | - | 20.00± 0.13 | - | -- | - | - | -- | - | - | ||
59136.06 | 20.07± 0.21 | - | -- | - | - | 18.65± 0.08 | - | -- | - | - | ||
59166.16 | 19.63± 0.09 | - | -- | - | - | -- | - | - | 18.55± 0.09 | - | ||
59382.34 | >15.690 | T | > 15.97 | - | -- | - | - | -- | - | - | ||
59441.28 | 19.30± 0.09 | - | -- | - | - | 18.28± 0.06 | - | -- | - | - | ||
59463.24 | 19.47± 0.09 | - | 19.56± 0.21 | - | -- | - | - | 18.51± 0.10 | - | |||
59523.12 | >16.760 | - | -- | - | - | 18.23± 0.06 | T | -- | - | - | ||
59548.02 | 19.41± 0.10 | - | 19.93± 0.12 | - | -- | - | - | 18.53± 0.10 | - | |||
59759.35 | 19.32± 0.22 | - | > 16.07 | - | 18.15± 0.07 | - | -- | - | - | |||
59794.23 | 19.44± 0.13 | - | -- | - | - | -- | - | - | 18.74± 0.13 | - | ||
59849.06 | >15.820 | - | > 15.81 | - | -- | - | - | -- | - | - | ||
59903.12 | 19.25± 0.08 | - | -- | - | - | 18.22± 0.06 | - | 18.48± 0.11 | - |
If the brightness variation is true variability then there should be a correlation between brightness changes recorded in different filter bands. The following table are the R-squared linear correlation factors calculated for the pairs of bands. The number in parentheses next to the R-squared value is the number of elements used to calculate the correlation factor. The number in square brackets next to the band is the range of magnitudes measured.
V [0.80 mag] | B [0.82 mag] | R [0.50 mag] | |
---|---|---|---|
B [0.80 mag] | 0.14 (12) | ||
R [0.50 mag] | 0.64 (16) | 0.61 (4) | |
I [0.95 mag] | 0.63 (13) | 0.00 (4) | 0.49 (6) |
The plots below are provided to check the values in the table above and also to show any non-linear correlations
Welch & Stetson (1993, AJ, 105, 1813) present a method for varible star detection in CCD images from automated surveys. Data from two bands are compared and two statistics are calculated: R and I.
The I-statistic has an expectation value of zero for stars that are NOT variable. A larger non-zero I-value indicates a higher likelihood that the star is variable. The R statistic indicates how the color of the star changes as the variable grows brighter with R = 1.0 being no change in color.
R and I values have only been calculated if there are more than four (4) matched measurements of brightness in each band.
V (I|R) | B (I|R) | R (I|R) | |
---|---|---|---|
B (I|R) | 1.01 | 0.74 | ||
R (I|R) | 2.23 | 0.82 | --- | --- | |
I (I|R) | 2.31 | 1.60 | --- | --- | 2.10 | 1.27 |
By John C. Martin, University of Illinois Springfield Henry R. Barber Research Observatory
Generated on 2023-08-14 14:15:12 UT-5