Amateur Exoplanet Archive (AXA)
                                                                                                                                                                                                                                         # Transit LCs
##  Object                 RA                Dec             V-mag        B-V          HJDo                 Period                Depth      Length        b        Season    (# OOT LCs)
                                                                         [days]       [mmag]  [hours]        [Month]

37  WASP-12   06:30:33 +29:40.3  11.69  0.42  4506.9761   1.091423    16.5   2.95  0.36  01.0    0(0)
36  CoRoT-4   06:48:47 -00:40.4  13.7   0.??  4141.36416  9.20205     14.0   4.42  0.??  01.0    0(0)
35  CoRoT-3   19:28:13 +00:07.3  13.29  0.91  4283.1383   4.25680      5.2   3.77  0.55  07.1    0(0)
34  CoRoT-1   06:48:19 -03:06.1  13.6   0.57  4159.4532   1.5089557   24.8   2.46  0.??  01.0    1(0)
33  HAT-P-8
  22:52:10 +35:26.8  10.26  0.??  4437.67582  3.076320     7.0   3.6   0.32  09.2    0(0)
32  WASP-11   03:09:29 +30:40.4  11.89  0.??  4729.90631  3.7224690   22.4   2.59  0.24  11.5    2(0)
31  HAT-P-9
  07:20:40 +37:08.4  12.30  0.50  4417.9077   3.92289     14.0   3.3   0.52  01.3    0(0)
30  WASP-10   23:15:58 +31:27.8  12.7   0.??  4357.85803  3.0927600'  37     2.14  0.58  09.4    6(0)
  WASP-14   14:33:06 +21:53.7   9.75  0.46  4465.81963  2.243756    11.7   2.78  0.51  05.1    1(0)
28  XO-5      07:46:52 +39:05.7  12.13  0.84  4485.6664   4.187732    13.8   3.05  0.55  01.5    7(0)
27  XO-4      07:21:34 +58:16.0  10.67  0.57  4485.9322   4.12502     09.7   4.58  0.18  01.4    8(1)              
26  WASP-7    20:44:10 -39:13.5   9.51  0.??  3985.0149   4.954658    10     3.67  0.08  08.1    0(0)
25  HAT-P-7   19:28:59 +47:58.2  10.5   ?.??  3790.2593   2.2047214'  07.1   3.88  0.37  07.4    8(0)
24  CoRoT-2   19:27:07 +01:23.0  12.57  ?.??  4237.53562  1.7429964   35.2   2.27  ?.??  07.4   12(1)
23  WASP-5    23:57:24 -41:16.6  12.26  ?.??  4373.99598  1.6284279   12.5   2.37  0.31  09.8    0(0)
22  WASP-4    23:34:15 -42:03.7  12.5   ?.??  4383.313070 1.3382324   34     2.12  0.06  09.7    1(0)
21  WASP-3    18:34:32 +35:39.7  10.64  ?.??  4605.55915  1.846834    12.2   2.71  0.51  07.0   12(0)
20  HAT-P-6   23:39:06 +42:28.0  10.54  0.34  4035.67575  3.852985    10.1   3.42  0.60  09.5    2(0)
19  HAT-P-5   18:17:37 +36:37.3  12.03  0.62  4241.77663  2.788491    14.0   3.0   0.42  06.9    4(0)
18  HD 17156  02:49:45 +71:45.2  08.17  0.64  4438.4824'  21.21649'   06.6   3.05  0.55  11.3    8(3)
17  HAT-P-4   15:19:58 +36:13.8  11.21  0.57  4245.8154   3.056536    09.6   4.2   0.01  05.6    3(0)
16  TrES-4    17:53:13 +37:12.7  11.34  0.48  4230.9053   3.553888'   14.5   3.53  0.75  07.2    5(1)
15  HAT-P-3   13:44:22 +48:01.7  11.86  0.8   4218.7566'  2.90088'    16.8   2.04  0.49  04.5   13(0)
14  XO-3               04:21:53 +57:49.0  09.80  0.45  4449.8672'  3.1915228'  09.8   2.87  0.70  12.0   23(2) 
13  GJ 436    11:42:11 +26:42.4  10.68  1.52  4280.78148  2.643904    08.1   0.95  0.92  03.5   38(9)
12  XO-2      07:48:08 +50:13.2  11.18  0.82  4147.74902  2.6158605'  14.2   2.67  0.16  01.5   32(3)
11  TrES-3    17:52:07 +37:32.8  12.40  0.71  4185.9107'  1.306186'   27.2   1.29  0.82  06.7   37(3)
10  HAT-P-2   16:20:36 +41:02.9  08.71  0.41  4213.4794   5.63341     05.5   3.46  0.54  06.0    0(0)
09  XO-1      16:02:12 +28:10.2  11.19  0.66  3808.91709' 3.941502'   23.5   2.91  0.73  05.9   38(4)
08  WASP-2    20:30:54 +06:25.8  11.98  1.02  3991.5138'  2.1522221'  19.5   1.74  0.39  08.0   18(5)
07  WASP-1    00:20:40 +31:59.4  11.65  0.54  3151.486    2.519955'   14.6   3.67  0.3   10.0   12(0)
06  TrES-2    19:07:14 +49:19.0  11.41  x.xx  3957.6372'  2.470600'   17.1   1.71  0.83  07.3   27(1)
05  HAT-P-1   22:57:47 +38:40.5  10.4x  0.6x  4363.94656  4.4652934   14     2.65  0.70  09.3    2(0)
04  HD 189733 20:00:43 +22:42.7  07.67  1.08  3988.8051'  2.2185629'  29.0   1.70  0.66  07.7   23(1)
03  HD 149026 16:30:30 +38:20.8  08.16  0.56  4327.37211  2.8758887   03.0   3.31  0.45  06.0    0(0)
02  TrES-1    19:04:10 +36:38.0  11.79  0.78  3898.87330' 3.0300703'  25.1   2.47  0.76  07.3   22(0)
01  HD 209458 22:03:11 +18:53.1  07.65  0.63  2826.628521 3.52474859  18.0   2.97  0.48  08.8    6(0)
00  TransitSearch (where LC submissions for TransitSearch candidates are displayed)                                                     6(0)

What's New? is a web page that records changes to the various AXA web pages.                                                Note: ' symbol indicates AXA fit value, not the "official" value
To see the light curve plots for an exoplanet, click on the exoplanet's name (if it shows a link).
To download an ephemeris spreadsheet (Excel) that shows transit times for all the BTEs for an observer's site coordinates, click here: BTE Ephem.
To see the light curve plots for TransitSearch candidates, click TransitSearchLightCurves. To see the TransitSearch list of possible transit times click TransitSearch (& use the "Candidate Assignments" link).

Abstract for the AXA Web Pages

This web page is a "public domain" archive for amateur observations of known "bright transiting exoplanets" (BTE), where "bright" means V-mag < 14. My intent is to "preserve" amateur observations at one convenient location and to promote sharing exoplanet observations by many observers to help in the search for anomalies that might lead to a greater understanding of exoplanet systems. Some light curves (LCs) are of transits and others are out-of-transit (OOT). The archive manager will enhance the LC by correcting for temporal trends and air mass curvature using the non-transit portion of data. A line-segment fit will be superimposed on the LC measurements. Each LC will be accompanied by a listing of mid-transit time, transit length, transit depth and an indication of whether the transit was early or late. A web page is devoted to each exoplanet, with the most recent LCs at the top. Observers of TransitSearch candidates are welcome to submit observations. It's OK that most of them will be featureless; this is useful information. A web page is devoted to LCs for TransitSearch candidates. It is anticipated that later in 2008 most of the data on the AXA will be transferred to the Caltech NStED archive. The fate of this web page will depend on how many of the AXA features are present at the NStED/AXA.

Links Internal to this Web Page:

    Best for this Season
    Purpose for this Archive
    Observation Submission Format
    Sampe of Archive Processed Product
    Explosive Growth of Exoplanet Discoveries
    Patterns to Look For
    Observing Philosophy
    Aperture vs. Technique
    Comment on Correcting LCs for Slope and Curvature
    Ground Rules for Professional Use of Data Files
    Related Links      

Best for this Season

Many exoplanets are "in season" in the winter months. HD 17156 continues to intrigue astronomers, professional and amateur alike. It is well situatied for winter observing, but with a period of 21.2 days each transit becomes a high-value target. The next few opportunities are December 19.88 (Europe) and January 10.10 (Europe and USA). HAT-P-8 is the latest discovery but it is observable for only 5 hours in mid-December (setting through 20 degrees elevation before midnight). WASP-11 and the newly-announced WASP-12 are perfectly situated for December observing and they need to be observed. HAT-P-9 needs observations (none in the AXA) but it's an early morning object. XO-3 is perfectly situated for December and January observations, but it is well characterized so I'm unaware of scientific value in observing it this year. XO-2, 4 & 5 are January and February objects, the 4 & 5 need observations. HAT-P-9 is a morning object, and so far the AXA has no observations for this BTE. GJ 436 is an early morning object, and it will merit observing for years to come.

Purpose for this Archive

This archive was promted by the fact that amateurs have no place to submit their observations of exoplanet transits where they will be processed and displayed in a useful format. Since it is scientifically important to preserve a historical record of transit light curves (LCs), and since LCs that are only present at an individual observer's web page are unlikely to be preserved for later use, there is an unmet need for an archive that collects amateur LCs and presents them in a uniform format. Such an archive will grow in value and could become a useful resource many years in the future. Only a handfull of amateurs are associated with a professional group of astronomers, where archives are preserved, and their LC archive is not in the public domain. The AXA is open for anyone to submit observations that are likely to be added to the AXA web pages and maintained as a historical archive.

The structure of the present archive allows for easy browsing for the purpose of visually searching for patterns that would otherwise be difficult to detect. I anticipate that professional astronomers with their own archive (not in the public domain) will glean information from this one as they search for patterns that can only be done with large amounts of LC data. In this way amateurs with good observing skills can contribute to the professional astronomy community's growing understanding of exoplanet systems, and possibly produce interest in anomalies that could lead to the discovery of additional exoplanets in the same exo-planetary system.

This web page describes how anyone who has observed an exoplanet, and produced a light curve (LC), can submit their observations and have them added to the archive. As the archive manager I will assess the quality of the data and if it looks acceptable (99% of submissions are acceptable) I will proceed to process it. Baseline systematics will be assessed and a fit to the data using a line-segment transit model will be over-plotted on the measured data points. The resulting LC plot will list mid-transit time, transit depth and transit length. Measured mid-transit time will be compared with an ephemeris predicted time. A notation may be made on the LC plot showing 2-minute RMS of the individual measurements.

When many transits are present on a web page devoted to an exoplanet, and ordered with the most recent LC at the top, it is easy to notice the following patterns: transists occuring early or late (implying a need for refining the orbital period), depths varying in a systematic way with filter (related to star spectral type and center miss distance) and transit length varying over time. Some of these patterns can be used by anyone to search for other exoplanets using mid-transit timing anomalies, called "transit timing variations" (TTV). Other patterns may justify a reconsideration of stellar limb darkening and center miss distance. A search for another exoplanet in the same system can also be performed using the OOT data that might contain small depth features that repeat with a different period than the main transits. Many archives exist with exoplanet transit information, but none are in the public domain, and perhaps none are structured in a way that is convenient to use for the purposes just mentioned. This web page is meant for those who are not associated with professional teams that maintain a "secret" archive.

Data File Format

This section used to include instructions for preparing a data file for submission to the AXA, but it has been moved to a separate web page: DataFormat. I'll simply show an example of a properly formatted data file and refer you to the above link for explanations.

Sample data submission showing required format.

Here's an example of my preferred filename convention: 20080301-gj436-GJL.txt. It conveys the information that the observations began on the date 2008 March 1 (UT), the object was GJ 436, and the observer's 3-letter "observer code" is GJL (details on the other web page). Attach this file to an e-mail sent to:

         a x a @ b r u c e g a r y . n e t  [remove spaces between characters]

Sample of Archive Processed Product 

Two light curve formats will be presented for each data submission (starting May 1). There will be a top panel LC, a bottom panel LC, and a 4-row information section between the panels. In the  following example the top panel is a version of the data with the two principal systematic errors removed (temporal trend and air mass curvature). This is the format used by professional astronomers. Since amateurs have larger systematic errors I have included the lower panel to show the same data before removal of these systematic errors. The lower panel also shows a air mass and "loss" plots (described below). For this example we can readily see that the early data were made at very high air mass, which explains the greater noisiness of the data and extreme air mass curvature.


The middle section states that the transiting object is XO-1, using a R-band filter, and mid-transit occurred on March 14, 2006 UT. The 7-segment model fit (explained in detail at model) has a mid-transit HJD of 2453808.9165 ± 0.0010. This corresponds to UT = 9.946 ± 0.015 (based on the date and source coordinates). The ephemeris predicted HJD and UT are also shown in the 3rd row (green). The transit length was measured to be L = 2.88 ± 0.03 hours, which is slightly longer than the consensus value of 2.91 hours. The transit depth is 23.0 ± 0.6 mmag, which is the same as the consensus value. Fp is the fraction of time the transit is "partial," defined using contact times as Fp = ((t2 - t1) + (t4 - t3)) / (t4 - t1). The solution for Fp is 0.25 ± 0.03. F2 is the ratio of depth at t2 and t3 divided by the depth at mid-transit, and for this solution F2 = 0.76 ± 0.22. The ephemeris HJDo and Period (used to calculate expected mid-transit time) are shown. The fitted temporal trend (-0.42 mmag/hour) and air mass curvature coefficient (+1.20 mmag / airmass) are given. The entry "Early: 0.6 ± 0.9 min" states that mid-transit was earlier than the ephemeris time by 0.6 minutes. You'll note that blue entries are specific to the submitted observations and green entries are from an ephemeris or a consensus of previous observations. The upper panel includes a plot of departures of the measured magnitudes from the model fit, or "O-C" (observed minus computed). The lower panel's large red circle data, with SE bars, are averages of non-overlapping groups of either 5, 7, 9, 11, 13 or 17 individual image values. At the bottom of the lower panel is a green trace showing "losses" offset so that their magnitude value is 1.0 when losses are zero (as read on the right side). Losses refer to the effect of clouds, dew on the corrector plate, wind shaking the telescope enough to broaden the point-spread-functionof all stars so that some of the photo electrons spill out of the aperture circle. For this example there was dew formation on the corrector plate that was evaporated with a hair dryer at 1.1 UT, and another dew formation just prior to the end of observations (~0.1 magnitude loss in both cases).

I've adopted this presentation because it is quicker to produce than previous versions. If Caltech really does assume responsibility for the AXA it won't be open for public submissions for at least 6 months, and during that time I want to minimize my workload. A program is used to perform chi-square fitting of submitted data and records a file that is easily imported to the spreadsheet which is screen captured as an image file for import to a web page. The entire process is much faster than the hand solution searches I used to perform, and this will enable me to accept more data submissions. If you preferred the other versions, requiring hand-entered values for such things as mid-transit time, length and depth, then I hereby apologize for abandoning them.

As stated above, a description is given of the very simple transit "model" used for fitting the submitted measurements at model fitting.

Explosive Growth of Exoplanet Discoveries

The number of bright transiting exoplanets has doubled in the past year (mid-2006 to mid-2007). There may be an equal number of undiscovered transiting exoplanets among the list of 246 exoplanets discovered spectroscopically (i.e., from radial velocity variations) found on the web site. There are plenty of observing opportunities for amateurs not associated with a wide field camera survey team, like the XO Project. Even an "arm chair" amateur astronomer can become engaged with a study of existing observations. There is merit in collecting all LC observations for each object and searching for patterns. One pattern would be transit timing variations (TTV) of mid-transit times; another would be a search for shallow transits during OOT times; and a search could even be made for LC structure within a transit or just outside transit by combining and averaging many LCs. For example, an exoplanet with rings may produce a brightening just before ingress and just after egress. Some day there may be a central archive where ALL exoplanet LC observations can be found. It is appropriate for either NASA or NSF to maintain such an archive. Caltech's IPAC archive would be an appropriate place for this addition. It would also be appropriate for a European institute to host the archive. Until this happens I would like to urge my fellow amateur astronomers to share their LCs on this public archive.

The rate of discovery of "bright transiting exoplanets" is growing exponentially with a doubling time of 1.1 years. The discovery rate of BTEs in the northern celestial hemisphere (orange) can serve as an estimate for what can be expected for the discovery rate of BTEs in the southern skies. By the end of 2008 there may be ~52 known BTEs using this model.

The first 21 BTE discoveries were in the north celestial hemisphere because until recently the wide field search cameras were only in the northern hemisphere. Now that southern hemisphere cameras are in operation it won't be long before there will be about as many BTEs in the southern skies. If we assume the discovery rate curve for BTEs in each celestial hemisphere has the same shape (doubling time) then the discovery rate curve for the NH (orange trace in above figure) can be shifted 2.4 years to show what can be expected for SH discoveries versus time (green trace, in above figure). By the time the list of  northern sky BTEs is complete to 14th magnitude the discovery rate curve will flatten out to some unknown limit which will depend on how many long period exoplanets are there to be discovered. This is unlikely to happen before the end of 2008, when this model predicts that we will know about 52 BTEs.

Patterns to Look for

If an exoplanet has a debris system in the same orbit (e.g., volcanic ejecta surrounding and perhaps following the "hot Jupiter" planet) the debris particles will "forward scatter " and produce brightness enhancements before ingress and after egress. The pre-ingress and post-egress brightenings should have a different brightening amount and shape. This effect is likely to be too small for detection using amateur observations but unusually large, transient ejection events should not be ruled out.

If an exoplanet has a ring system the ring particles will also "forward scatter" and produce a brightening before ingress and after egress that can last several minutes. In 2004 Joe Garlitz and I independently noticed that amateur LC observations of TrES-1 showed a small brightening (~5 mmag) after egress, lasting ~10 minutes. Ron Bissinger did an exhaustive statistical analysis of many TrES-1 LCs and concluded that the feature was statistically significant. Subsequent HST observations failed to confrim the feature so we are left to assume that the apparent brightenings were a statistical fluke. All exoplanets should be inspected for such a feature even though the effect is probably going to be much smaller than amateur observations could detect (< 0.3 mmag according to Brown and Fortney, 2004 and Otha et al, 2008).

An exoplanet may have a moon of its own, and if its large enough it could produce a small fade either before ingress or after egress. This would probably be noticed as a change in mid-transit time since on any one transit the moon will affect only an ingress or only an egress for a given transit. Brown et al (2001) searched for this effect with HST observations of HD 209458 and found nothing. Again, amateur observations are likely to be insufficiently precise to observe such an effect unless the moon is comparble in size to the hot Jupiter. 

Mid-transit time can vary if the exoplanet is accompanied by another exoplanet in an orbit with a period resonance, such as 2:1, 3:2, etc. For exoplanets with a long record of transit timing measurements these timing anomalies should be searched for.

Transit length and depth can vary if the transiting planet is close to "grazing" and another planet in a nearby orbit that inclined differently causes changes in the transiting planet's inclination. This was thought to be the situation for GJ 436 in January 2008 (Ribas et al, 2008a; Ribas has since withdrawn this suggestion in the light of later observations that offered a simpler interpretation). Still, any exoplanet with an "impact parameter" close to 1, such as GJ 436, TrES-2, TrES-3 and HD 17156, should be viewed as candidates for transit property changes due to inclination changes caused by another exoplanet in a resonant orbit.

If an exoplanet has Trojan planets (same orbital period but located at longitudes 60 ahead or behind) there may be a detectable fade at times that are offset 1/6 of a period before or after the main exoplanet transit event. For hot Jupiter periods of 3 days, for example, the Trojan features will occur ~12 hours before or after the ephemeris transit. This offset is longer than any single transit observing session, so only the OOT observations can be used for this purpose.

Sunspots will produce a small brightening during the interval Contact 2 to Contact 3 but they'd have to be large to be detected by amateur hardware. If a feature is seen on one LC it may not be seen on others unless the periods are the same (period of exoplanet orbit and period of rotation at the sunspot's latitude).

Observing Philosophy

On a typical night at least one of the BTEs will undergo a transit. On those nights when none are observable check the TransitSearch candidate list. If no known BTE transits are on the schedule, and the TransitSearch candidate list is unappealing for the night, there is merit in conducting OOT observations of a BTE. Preference can be given to exoplanets that are ~1/6 of a period away from transit, since that's when Trojans would produce their transit signatures. Another consideration is "impact parameter" - the ratio of closest approach miss distance to star radius. Small impact parameters are good candidates for second exoplanet transits in outer orbits. Small impact parameter systems have flatter bottomed transit shapes (i.e., contact 1 to contact 2 is short compared with contact 2 to contact 3).

If your interest is in a search for LC transit shape anomalies, either brightenings or fadings before ingress and after egress, then give preference to observing a bright exoplanet. Although scintillation will be the same regardless of a star's brightness, the SNR (caused by Poisson noise) will be better for brighter stars.

May I suggest that you "adopt" an exoplanet that transists near midnight and simply observe it every clear night. After inspecting it for anomalies that you can hope are real and repeating with an unknown period, the overall OOT shapes can at least be used to learn about your observation's systematics. For example, an OOT set of measurements would produce a LC that is "flat" and "horizontal" if no systematics were present. However, if your polar axis is slightly mis-aligned (>0.1 degree), and if your master flat field is imperfect, the LC will have a sloping trend of as much as several mmag per hour. If a small scale feature in the master flat is imperfectly represented (such as a dust donut) then features could be superimposed on the sloping trend line. A hot or cold pixel (or imperfect master dark frame) could produce the same features. Another systematic, that is quite common, is for the OOT LC to be curved in a way that is related to air mass. This arises when the exoplanet star is not the same color as the reference star (or the average color of the reference stars, if ensemble photometry is employed). If your OOT observations produce an LC with a curvature that is correlated with air mass then you may want to give attention to reference star color when choosing reference stars.

I have slowly come to appreciate some fundamental differences between the kind of variable star observing and image analysis performed for the AAVSO versus that required for exoplanets. Occasionally a new observer will be handicapped by adhering to traditional variable star observing procedures. For these observers I recommend reading a web page I created that describes the observing task differences, and how observing strategy and image analysis should be adjusted on behalf of the exoplanet task: Exoplanet Stars Are Not Variable Stars.

Aperture versus Technique

Whenever someone asks "what hardware is needed for observing exoplanet transits" I try to explain that a more relevant question to ask is "how competent an observer must I be for observing exoplanet transits?" This idea has been dramatically demonstrated by an observation that has recently come to my attention. Petr Svoboda (Czech Republic) used a 1.33-inch aperture "telescope" (actually, a 34 mm aperture camera lens) with a SBIG ST-7 CCD camera to obtain the following light curve:

Small aperture light curve made with a 1.33-inch "telescope" (34 mm camera lens).

Another impressive demonstration comes from Gregor Srdoc (Croatia) who used a 2.5-inch camera lens attached to a regular DSLR camera (12-bit) to measure a 9.5 mmag depth transit of XO-4. The message from these two examples is that "aperture isn't everything" because technique is important regardless of aperture. Technique is based on an understanding of observing concepts, image analysis and data analysis. I believe that it's difficult to teach any of this because the best way to learn is to "flounder" with whatever hardware is available! So my advice to anyone who wonders what hardware is needed for exoplanet transit observing is to change the question to "how willing am I to learn from floundering with whatever hardware I have?" And remember, floundering is fun!

Comment on Correcting LCs for Slope and Curvature

I disagree with the custom of professional astronomers who present transit light curve plots that have been "corrected" for a temporal trend and an air mass (extinction) correlation. The viewer has no clue about the magnitude of either correction when viewing a plot with those effects removed. As I show in my book Exoplanet Observing for Amateurs (Chapter 14, pg 82) the presence of these corrections influence such "transit parameters" as depth, shape, length and mid-transit time. There usually is a locus of points in slope/curvature parameter space (temporal slope and air mass coefficient) having equally good fits yet yielding varying results for transit parameters. Because of my experience with hand-fitting the LCs by experimenting with values for slope and curvature, and seeing the effect these choices have on transit parameters, I am reluctant to accept elaborate solutions for planet radius in a paper where there is no discussion of the slope/curvature fitting ambiguities. It's potentially misleading to simply experiment with the slope and curvature coefficients until the LC looks good, and then proceed with an elaborate chi-squared analysis seeking solutions for planet size, inclination, limb darkening, etc. without also including the slope and curvature coefficients as independent variables. Consider the following innocent-sounding description: "We then fit a linear function of time to the pre-ingress and post-egress data. A function of time proved to be a slightly better fit than the more traditional function of airmass." (reference available upon request).

I have adopted the practice of preserving the uncorrected photometry data points while applying the temporal trend and air mass correlated solutions to the "model fit" trace. These LCs may not look as pretty as the ones professionals publish, but they convey more information and are a more honest representation of the LC that was measured. Therefore, if you're used to seeing the pretty LCs with slope and curvature corrections removed, think twice before passing judgement on the sloped and curved LCs you see on the AXA web pages for each exoplanet.

I plan on adding a link to an illustration of quantitative effects upon transit parameters when the slope and curvature corrections are treated carelessly.

Ground Rules for Professional Use of Data Files

The description of various versions of these "ground rules" can be found at: GoundRules  A short version that will be included in the header of those data files that are transferred to Caltech's IPAC computer (NStED archive), in late 2008, is presented here:

"Downloading of amateur data files is unrestricted. However, since these data are unpublished it is recommended the observer be contacted prior to use of data. The observer may be aware of specific aspects of the data that should be taken into consideration when interpreted, such as seeing, clouds, wind, scintillation, clock-setting procedures, optimized photometry apertures, etc. If these data are to be used in a publication, it is requested that the observer be acknowledged by name along with a brief description of the hardware used."


AXA and TransitSearch contributors (top of list is the most frequent contributor). The contributor list is divided into two categories: "active and "inactive." To be "active" an observer must have contributed at least one observation during the previous 6 months (the date of the observation is not relevant).  (Three of the observers on the lists are more active than they appear since they are contributors to the XO Project and only some of their observations can be submitted to the AXA; they are Foote, Gregorio and Vanmunster.)

    Total number of LC submissions ......       405

       Active Observers & their Code     Obs'g Site             TotNr    Submissions (during previous 6 months)*

    Manuel Mendez        (MQZ)  Spain            27   8b25,8b16,8b14,8b11,8b06,8b01,8829,8825,8826,8814,8812,8812,8731,8729,8724,8710,8710,8709,8708+
    James Roe            (ROE)  Missouri         26   8918,8918,8903,8819,8801,8808,8804,8729,8729,8729,8615,8617,8612,8611,8528,8525,8522,8521,8521+
    Cindy Foote          (FC2)  Utah (USA)       54   8c11,8b18,8b17,8a29,8903,8903,8624,7b13,8607,8607,8607,7a25,7a25,7a09,7a09,7215 & many others
    Veli-Pekka Hentunen  (HVP)  Finland          21   8a29,8b06,8b06,8b06,8b06,8b01,8b01,8b01,8a29,8a29,8a29,8a18,8a18,8a18,8a18,8a18,8a18,8a18,8a17+
    Anthony Ayiomamitis  (AA2)  Greece           15   8b26,8b22,8a08,8a05,8906,8903,8902,8709,8628,8626,8613,8606,8603,8528,8503
    Bruce Gary           (GBL)  Arizona, USA     72   8c10,8b30,8b14,8b08,8b02,8a28,8a22,8a18,8a17,8a15,8a14,8701,8602,8603,8528
    Ramon Naves          (NR2)  Spain            34   8b29,8a06,8915,8909,8818,8818,8814,8814,8803,8803,8719,8622,6507
    Gregor Srdoc         (SG2)  Croatia          17   8a27,8630,8625,8609,8601,8602,8528,8514,8512,8507,8503
    Joao Gregorio        (GJ2)  Portugal         22   8c20,8c16,8c14,8c05,8a05,8127,8120,8302
    Yenal Ogmen          (OYE)  Cyprus            7   8a11,8907,8922,8724,8710,8702,8630
    Standa Poddany       (PS2)  Czech Republic    6   8a23,8905,8905,8827,8716,8627
    Fabio Salvaggio+     (SFV)  Italy             5   8901,8901,8706,8616,8614
    Enric Forne          (FE2)  Spain             4   8c16,8929,8929,8929
    Ricard Casas         (CRI)  Spain             4   8929,8929,8929,8929
    Nicolaj Haarup       (HNI)  Denmark           5   8413,8320,8319,8318
    Toni Scarmato        (SFI)  Italy             3   8c06,8b20,8814
    Miguel Rodriguez     (RMU)  Spain             3   8809,8512,8415

    Peter Kalajian       (KP2)  Maine             2   8908,8911
    Gustav Muler         (MG2)  Canary Islands    2   8914,8301 
    Tonny Vanmunster     (VMT)  Belgium          34   8511,8511
    Darrel Moon          (MD2)  Utah              3   8704,8703
    Giuseppe Marino      (MG3)  Italy             2   8717,8616
    Josep M Coloma       (CJI)  Spain             1   8c16
    Petr Svoboda         (SP2)  Czech Republic    1   8b03
    Ramon Costa          (CR2)  Spain             1   8929

    Joal Bel             (BJ2)  Spain             1   8929
    Xavier Puig          (PX2)  Spain             1   8929

    Fernando Tifner      (TF2)  Argentina         1   8924
    Stelios Kleidis      (KSM)  Greece            1   8607
    Bart Staels          (SBL)  Belgium           5   8207
    Colin Littlefield    (LC2)  Indiana, USA      1   8B22

    * Date code is YMDD. Example #1: 20080317 = 8317; Example #2: 2007 December 31 = 7c31 (think HEX). Starting July 8 entries will be for date of submission, not observing date.

Some of the 3-letter observer codes for the active observers have links to description of hardware (and picture of hardware with observer).

Note: I salute the Europeans for their involvement with exoplanet observations and contributions to the AXA. Most of the active contributors are Europeans, although the most prolific contributor is in Utah.

    Exoplanet Observing for Amateurs (book)
    Useful spreadsheets (BTE_ephem.xls, etc)
    Jean Schneider's Extrasolar Planet Encyclopaedia
    Greg Laughlin's TransitSearch archive
    NStED (Caltech's NASA/IPAC/MSC Star and Exoplanet Database)
Bruce's AstroPhotos

WebMaster: B. GaryNothing on this web page is copyrighted. This site opened:  2007 August 06,  Last Update:  2008.12.20