M31-004021.21 (J004021.21+403117.1)

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Target Notes

Classification: -

No blend concerns

Photometry Table

MJD	V	*	Image	B	*	Image	R	*	Images	I	*	Images
56599.13	16.67± 0.03	-		16.92± 0.04	-		16.48± 0.04	-		--	-	-
56604.11	16.68± 0.03	-		16.98± 0.03	-		16.46± 0.05	-		--	-	-
56930.16	16.67± 0.03	-		16.98± 0.04	-		16.46± 0.04	-		--	-	-
56951.10	16.69± 0.04	-		17.00± 0.03	-		16.49± 0.05	-		--	-	-
57307.14	16.66± 0.04	A		16.96± 0.03	A		16.47± 0.04	A		--	-	-
57340.22	16.63± 0.06	-		--	-	-	--	-	-	16.21± 0.08	-
57634.30	--	-	-	16.96± 0.04	T		16.46± 0.06	T		--	-	-
57638.23	16.66± 0.05	-		16.96± 0.05	-		16.49± 0.07	-		16.28± 0.07	-
57743.02	16.79± 0.04	-		17.06± 0.03	-		16.57± 0.02	-		16.36± 0.04	-
57958.38	16.72± 0.03	-		--	-	-	16.52± 0.04	-		16.30± 0.04	-
57963.33	16.67± 0.04	A		16.96± 0.03	A		--	-	-	16.28± 0.07	-
57964.26	16.71± 0.04	-		--	-	-	16.53± 0.04	-		--	-	-
57988.31	16.76± 0.03	-		17.03± 0.04	-		--	-	-	16.34± 0.04	-
58035.07	16.58± 0.06	-		--	-	-	16.36± 0.07	-		--	-	-
58045.10	16.73± 0.03	-		17.02± 0.04	-		16.53± 0.04	-		--	-	-
58067.14	16.72± 0.03	-		--	-	-	--	-	-	16.30± 0.04	-
58073.12	16.75± 0.04	-		16.98± 0.05	-		--	-	-	--	-	-
58077.14	16.76± 0.04	-		17.01± 0.03	-		--	-	-	16.37± 0.07	-
58098.18	16.71± 0.03	-		--	-	-	--	-	-	16.33± 0.04	-
58103.11	16.75± 0.03	-		17.02± 0.04	-		--	-	-	16.27± 0.05	-
58316.31	16.71± 0.04	A		16.97± 0.04	A		16.50± 0.04	A		--	-	-
58317.29	16.68± 0.04	A		--	-	-	--	-	-	16.27± 0.06	A
58339.32	16.68± 0.04	-		16.97± 0.04	-		16.48± 0.05	-		--	-	-
58342.23	16.68± 0.03	-		17.02± 0.03	-		--	-	-	16.29± 0.04	-
58372.15	16.70± 0.03	A		--	-	-	--	-	-	16.24± 0.05	A
58373.13	16.63± 0.04	-		16.95± 0.05	-		--	-	-	--	-	-
58403.14	16.66± 0.03	-		16.92± 0.03	-		--	-	-	--	-	-
58433.06	16.67± 0.03	-		16.98± 0.03	-		16.49± 0.03	-		--	-	-
58672.33	16.70± 0.03	A		17.01± 0.03	-		16.45± 0.04	-		16.26± 0.05	-
58695.25	16.68± 0.03	A		16.99± 0.04	-		16.51± 0.03	-		16.30± 0.04	-
58757.06	16.71± 0.03	-		--	-	-	16.50± 0.03	-		--	-	-
58779.11	16.66± 0.03	-		--	-	-	16.47± 0.03	-		--	-	-
58784.02	16.64± 0.04	-		16.93± 0.04	-		--	-	-	--	-	-
58836.09	16.71± 0.02	A		--	-	-	16.50± 0.03	-		16.25± 0.04	-
59001.40	16.78± 0.05	T		--	-	-	--	-	-	--	-	-
59019.39	16.80± 0.03	-		17.19± 0.06	-		--	-	-	--	-	-
59026.34	16.72± 0.04	A		--	-	-	16.50± 0.05	-		--	-	-
59059.28	16.73± 0.03	A		17.02± 0.03	A		16.55± 0.04	-		16.30± 0.06	-
59081.20	16.75± 0.04	-		--	-	-	--	-	-	16.32± 0.07	-
59082.29	16.70± 0.04	-		17.00± 0.04	-		16.52± 0.05	-		--	-	-
59131.15	16.73± 0.04	A		17.06± 0.04	-		16.53± 0.04	-		--	-	-
59166.22	16.76± 0.03	A		--	-	-	--	-	-	16.36± 0.07	A
59194.17	16.74± 0.04	A		17.02± 0.03	-		16.54± 0.04	-		--	-	-
59380.36	16.76± 0.05	A		17.01± 0.04	-		16.61± 0.06	-		--	-	-
59415.32	16.74± 0.04	-		--	-	-	16.55± 0.06	-		--	-	-
59441.34	16.78± 0.03	A		17.09± 0.03	-		--	-	-	16.33± 0.06	A
59463.12	16.78± 0.03	-		--	-	-	--	-	-	16.36± 0.06	-
59483.12	16.77± 0.03	A		17.05± 0.04	-		16.54± 0.04	-		--	-	-
59523.05	16.73± 0.04	A		17.04± 0.04	-		16.51± 0.05	-		16.28± 0.06	-
59548.10	16.76± 0.04	A		17.04± 0.04	-		16.56± 0.04	-		16.35± 0.06	-
59759.37	16.80± 0.05	-		17.08± 0.05	-		16.59± 0.05	-		--	-	-
59794.28	16.77± 0.03	A		17.02± 0.04	-		--	-	-	16.41± 0.06	-
59823.20	16.71± 0.04	-		--	-	-	16.50± 0.05	-		--	-	-
59849.13	16.74± 0.03	A		--	-	-	--	-	-	16.38± 0.06	A
59903.06	16.80± 0.03	-		17.07± 0.03	-		16.59± 0.04	-		--	-	-
59904.08	16.72± 0.03	-		--	-	-	16.54± 0.04	-		16.36± 0.06	-
59932.06	16.74± 0.03	A		17.00± 0.03	-		--	-	-	16.40± 0.06	-

Plots of Brightness and Color

Variability

It is likely that this star is variable.

Correlation factors between bands

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 [0.27 mag]	B [0.22 mag]	R [0.25 mag]
B [0.27 mag]	0.68 (36)
R [0.25 mag]	0.83 (33)	0.54 (24)
I [0.20 mag]	0.52 (27)	0.06 (15)	0.69 (10)

Magnitude-Magnitude Plots

The plots below are provided to check the values in the table above and also to show any non-linear correlations

I & R Statistics

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)	1.63 | 0.81
R (I|R)	1.08 | 1.09	0.34 | 0.08
I (I|R)	0.68 | 1.30	0.19 | 0.94	0.73 | 1.42