XO-5
AXA Light Curves, Finder Chart & All-Sky Photometry Results

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Basic data
Summary of transit solutions
Transit LCs
Out-of-transit LCs
All-sky photometry
Finder Image

Basic data

RA = 07:46:52.0, DE = +39:05:40
Season = Jan 15
B = 12.978
± 0.030, V = 12.135 ± 0.030, Rc = 11.665 ± 0.030, Ic = 11.306 ± 0.05, B-V = 0.843 ± 0.05 (all-sky, all SE are total SE, orhtogonal sum of formal statistical and estiamted systematic SEs)
HJDo = 4485.6664 (4) & P = 4.1877539 (84) day (Schneider's Extrasolar Planets Encyclopedia)
HJDo = 4485.6671 (6) and P = 4.187772 (2) days (Suggested new ephemeris based on AXA fit, below)
Depth = 13.7
± 0.9 mmag (R-band)
Length = 3.02
± 0.07 hr
Fp = 0.27
± 0.08 (fraction of transit that's partial)
F2 = 0.80 ± 0.15 (ratio of depth at contact #2 to mid-transit)
Impact parameter, b = 0.55
± 0.09

Nothing unusual yet.

Summary of Transit Solutions

Note: There are many more observations of this exoplanet made by the XO Project "extended team" of amateurs that have not been submitted to the AXA. I tried!

Light Curves

Out-of-Transit (OOT)

All-Sky Photometry

Here's an image showing XO-5 (formerly referred to as "2190") and nearby stars.

Figure 1.
XO-5 (formerly referred to as "2190"), FOV = 16 x 11 'arc, north up, east left. Star numbers are shown for the table in the next figure.

Figure 2. Weighted average magnitudes of XO-5 ("x2190") and nearby stars using all-sky measurements from all (3) all-sky observing dates.

Here's a summary of XO-5 all-sky magnitude measurements:

 XO-5       B-mag = 12.978 ± 0.029 (formal SE)     V-mag = 12.135 ± 0.013 (formal SE)     R-mag = 11.665 ± 0.013 (formal SE)     I-mag  = 11.306 ± 0.018 (formal SE)

Figure 3. Summary of various V-mag & R-mag estimates for XO-5 (formerly known as "2190").

To see a large-format LRGB image of "2190" for the purpose of verifying that stars that should be blue and red according to the above table are in fact blue and red, click LRGB_2190.

Table I: Number of Landolt Star Fields and Number of Landolt Stars Used in All-Sky Solutions
 Observing Date Landolt Fields BLU VIS RED inf 2008.01.10 6 36 37 19 19 2008.01.19 5 29 48 39 37 2008.01.20 2 0 10 8 0

Estimated total SE values (orthogonal sum of statitical and systematic SEs) are 0.03, 0.03, 0.03 and 0.05 mag. The B-V SE is 0.05 mag.

Figure 4. Color-color scatter diagrams showing that the XO-5 star field has similar color relationships to those in the set of Landolt stars, thus validating the quality of the all-sky observations reported here.

These are "internal consistency checks." It passes!

I conclude that interstellar reddening biases the Tycho V-mag value, and might also influence the conversion from J and K to V. The two all-sky measurements provide a consistent result that is free of the interestellar reddening biases. which argues for V-mag = 9.80 ± 0.03.

Finder Image

Figure 5. XO-5 {"2190"), FOV = 16 x 11 'arc, north up, east left.

Here's a reference to the "discovery paper" for XO-5:

"XO-5b: A Transiting Jupiter-sized Planet with a Four Day Period," Christopher J. Burke, P. R. McCullough, Jeff A. Valenti, Doug Long, Christopher M. Johns-Krull,  P. Machalek, Kenneth A. Janes, B. Taylor, Michael L. Fleenor, Cindy N. Foote, Bruce L. Gary, Enrique Garcia-Melendo, J. Gregorio, T. Vanmunster  http://fr.arxiv.org/abs/0805.2399