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Planet or fake? Check yourself - the PLATO-TESSt with small telescopes

2020-08-17; Ephemerides: 2020-08-17

The PLATO space telescopes are designed to find and measure terrestrial planets with orbits typical for the inner solar system. PLATO will go were its precursors CoRoT an Kepler had to stop. It will measure bright stars, as the NASA mission TESS already does, in search for shorter period planets. This provides a unique opportunity to gain experience with small telescopes, an experience that will be needed once PLATO is in orbit.

The data obtained will serve the support of TESS and the development of an optimised instrument, the PLATO PlanetValidator, which will be tuned for testing the planet candidates of bright stars. The PlanetValidator will also allow the measurement of the properties of large PLATO-planets with small telescopes.

PLATO's and TESS' return to the bright stars puts small telecopes back into the focus of astronomy. They allow tests of PLATO and TESS transit-signals: are they "true" planets or "fake" signals?

Recommended equipment / experience:

Starting now, selected current planet candidates will be made available at the Exoplanet Transit Database (ETD) listed as planet candidates. ETD provides coordinates, finder-charts, transit- predictions, and a search for transits for given observing location. Results can be uploaded to ETD, including a simple automatic analysis. Directly to the list of ETD-TOI-transits for the next day

All these candidates have been listed by the NASA-mission TESS and they are part of the TESS TOIS release programme. These candidates are signals the are planet-like according to the quick-look of the TESS-team. Some of the signals detected by TESS are due to known planets discovered by the space missions CoRoT, Kepler, K2, and ground based searches as WASP, HAT, KELT, .... . They will not extra added to the ETD as TESS-candidates, but may appear in the transit prediction ephemerides below, marked with their discovery programme (CoRoT, Kepler, ...).

An explanation of TESS compared to PLATO is available on the PLATO-Consortium-pages.

More information below.

The brightest TOI-transits für Europe

Updated: see top of page: Athens, Barcelona, Berlin, Bucharest, Canary Islands, Dublin, Helsinki, Lisbon, London, Paris, Praha, Rome, Warsaw.

Next updates mid July

The following candidates are currently recommended for small-telescope-tests for PLATO-preparations

Summer 2020 TOI-selection

OBJECT        RA          DE           PERIOD     EPOCH        mag_T  DEPTH  DURATION  Con mag_V Depth
           [HH MM SS.ss] [DD mm ss.ss]   [d]      [JD]         [mag]  [mag]  [min]   [IAU] [mag] [%]
------------------------------------------------------------------------------------------------------
TOI 1455.01 20 34 40.78   66 26 25.06   3.62339  2458714.3918  10.2  0.0178   155     Cep  10.6  1.63 1455.01 next transits (ETD)
TOI 1568.01  0 35 57.29   65 01 34.24   1.35932  2458765.4757   9.7  0.0031   169     Cas  10.1  0.28 1568.01 next transits (ETD)
TOI 1480.01 22 10 27.27   63 33 02.02   3.35404  2458742.1405   8.8  0.0110   128     Cep   9.2  1.01 1480.01 next transits (ETD)
TOI 1168.01 20  6 50.50   38 25 51.74     2.136  2458684.8446  10.4  0.0116   104     Cyg  10.8  1.07 1168.01 next transits (ETD)
TOI 1516.01 22 40 20.26   69 30 13.45   2.05603  2458765.3253  10.4  0.0181   169     Cep  10.8  1.66 1516.01 next transits (ETD)
TOI 1518.01 23 29 04.22   67 02 05.38   1.90261  2458766.1206   8.8  0.0099   122     Cep   9.2  0.91 1518.01 next transits (ETD)

Recommended Spring 2020 TOI-selection

OBJECT        RA          DE           PERIOD     EPOCH        mag_T  DEPTH  DURATION  Con mag_V Depth
           [HH MM SS.ss] [DD mm ss.ss]   [d]      [JD]         [mag]  [mag]  [min]   [IAU] [mag] [%]
------------------------------------------------------------------------------------------------------
TOI 1297.01 13  3 17.11   67 49 24.28   3.93034  2458686.9387  11.0  0.0106   220     Dra  11.4  0.97  1297.01 next transits (ETD)
TOI 1405.01 21  2 40.58   70 04 49.11  12.64001  2458739.8801   8.4  0.0103   413     Cep   8.8  0.95  1405.01 next transits (ETD)
TOI 1460.01  1 22 26.54   26 55 32.70  6.842651  2458765.2652   9.9  0.0089   200     Psc  10.3  0.81  1460.01 next transits (ETD)
TOI 1305.01 18 49 53.94   55 15 59.50   7.85021  2458687.7993  10.0  0.0161   422     Dra  10.4  1.47  1305.01 next transits (ETD)
TOI 1355.01 22  5 13.79   66 46 30.95   2.17026  2458740.2368   8.7  0.0066   133     Cep   9.1  0.61  1355.01 next transits (ETD)
TOI 1431.01 21  4 48.86   55 35 16.51   2.65044  2458712.6753   7.8  0.0062   151     Cep   8.2  0.57  1431.01 next transits (ETD)

Recommended Winter 2019/20 TOI-selection

OBJECT        RA          DE           PERIOD     EPOCH        mag_T  DEPTH  DURATION  Con mag_V Depth
           [HH MM SS.ss] [DD mm ss.ss]   [d]      [JD]         [mag]  [mag]  [min]   [IAU] [mag] [%]
------------------------------------------------------------------------------------------------------
TOI 1575.01  3 27 57.28   54 51 56.47   2.46094  2458793.1746  10.4  0.0060   185     Per  10.8  0.55 
TOI 1582.01  2 18 47.50   64 21 23.02   1.89253  2458791.8149  10.0  0.0154   207     Cas  10.4  1.41 
TOI 1568.01  0 35 57.29   65 01 34.24   1.35932  2458765.4757   9.7  0.0109   169     Cas  10.1  1.00 1568.01 next transits (ETD)
TOI 1297.01 13  3 17.11   67 49 24.28   3.93034  2458686.9387  11.0  0.0106   220     Dra  11.4  0.97 1297.01 next transits (ETD)
TOI 1553.01  1 38 45.71   42 40 40.02   5.93815  2458768.4070  10.3  0.0055   148     And  10.7  0.51 

TOI 1366.01 22 30 44.75   40 00 14.28   7.43062  2458745.7885   8.5  0.0088   197     Lac   8.9  0.81 
TOI 1405.01 21  2 40.58   70 04 49.11  12.64001  2458739.8801   8.4  0.0103   413     Cep   8.8  0.95 1405.01 next transits (ETD) Do not observe! False Positive
TOI 1608.01  3 23 12.14   33 04 42.18    2.4724  2458792.4602   7.4  0.0033   132     Per   7.8  0.31 
TOI 1147.01 17 47 50.92   83 25 43.23  10.91462  2458692.1528   8.4  0.0041   106     Dra   8.8  0.37 
TOI 1460.01  1 22 26.54   26 55 32.70  6.842651  2458765.2652   9.9  0.0089   200     Psc  10.3  0.81 1460.01 next transits (ETD)

A brief introduction with a few remarks

A "TOI" is a "TESS object of interest", that means it is considered and rated "interesting" by the TESS team. Here we discuss only TOIs that are labelled as PC (planet candidate).
TOI 294.01 - easy transit, fainter star
With a depth of more than 1% the signal is easy to reach for the experienced amateur and can be directly confirmed if all goes well. The star, however is relatively faint by TESS and PLATO standards and may not be so easy to identify for the beginner. With seven days it shows an interesting period and the chances are quite good that this is a "real" planet.
TOI 00294.01 @ ETD
1405
TOI 00469.01 - very interesting, bright and easy to find by difficult to catch the transit
Very interesing case, if it is a planet. In that case it would have abou 1/6th of mercury's orbital period and would be one of the longest period planets TESS is able to routinely detect. With 8.4 mag it is an easy object for binoculars (to see, not to measure) und can be comfortably located between Sirius and Orion's belt. The signal itself is 1 permille (1/1000) and cannot be reached with small telescopes. Here the goal is prove the constancy of the neighbouring stars. This is an important contribution to to make sure that the TESS signal is actually "on the correct star". Because the transits occur only every two weeks they are hard to catch.
TOI 00469.01 @ ETD
TOI 00498.01 - many transits, "medium" bright starn, small signal
Because of the short period there are frequent opportunites to observe this signal "on transit". An ideal opportunity to practice finding and observing on time, the essence of "time critical" observations. The star is located almost on the celestial equator, in the constellation of Hydra. The scientific focus is to check the constancy and detect any "fake-signals" on the neighbours.
TOI 00498.01 @ ETD
TOI 00503.01 - conveniently located in cancer - the challenge for experts in this selection
With 9.2 mag this is a bright star and the transit signal is big enough to possibly be detected with small telescopes at the larger end in the hands of eperienced observers. All things considered this looks like a real planet, the period of about 4 days is in the planetary comfort zone, small indications for a grazing transit that fittingly with that conjecture is somewhat short for the period. For our test it is an ideal case because it is easy to find on the sky and with almost 13° N it is quite high on the sky for the current TESS batch. As a first step in the training I recommend to proof the constancy of the neighbours. If all goes well an with some luck expert may perhaps succesfully detect this transit directly and proof it from the ground for the first time.
TOI 00503.01 @ ETD
TOI 00522.01 - bright, convenient, "super-earth"-feeling, no direct detection with small telescopes, but exclusion of fake signals is necessary
With 7,4 magnitudes this is almost visible for the naked eye and certainly with an "opera glass". A unique opportunity to enjoy the "feeling" of a "super earth" candidated for a bright star. It would be a planet with 2 earth radii, if it is real. Unfortunately the same fact has the comnsequence in that case the transit signal of about 0.0001% is not reachable from the ground. Small telescopes can however uncover and resolve the case if it is a fake signal, a result of a non-constant neighbouring star. It may well be a signal of a star far behind the main source, a binary star somewhere in the galaxy, maybe as faint as 16th mag. Because the star is relatively large and hot, I think it is unlikely that even in case the planet is confirmed, an (accurate) mass measurement will be made in the foreseeable future. An ideal case to get an idea about how the "Earth 2" discovery may feel, but unlikely to be a real case.
TOI 00522.01 @ ETD
TOI 00547.01 - also known as CoRoT-1b (listed here for control purposes)
CoRoT-1 with its large planet that reduces its stellar brightness by more than 2% should be an easy case and a simple detection. But the problem is the weak star, that makes the measurement challenging, because the star is hard to find and difficult to identify. For its detection a telescope with a diameter of more then 40 cm is recommended.
TOI 00547.01 @ ETD CoRoT-1b Nachweise in der ETD:
The TOIs usually correspond to known stars. To avoid missidentifications in any case they are a renumbering of light-sources that the TESS-team found on their exposures.
ETD-FORMAT-TEST: List of recommended TOIs for PLATO-TESSt observations of TESS-candidates.

OBJECT        RA          DE           PERIOD(d)  EPOCH        mag_T  DEPTH DURATION
                                                               (mag)  (mag) (min)
--------------------------------------------------------------------------------
TOI 00294.01 22 36 06.31 -16 59 59.83   7.32829  2458358.7813  11.4  0.0115  176  Aqr
TOI 00469.01  6 12 13.97 -14 39 00.13 13.632935  2458474.5674   8.7  0.0011  265  Lep 
TOI 00498.01  8 36 21.81 -03 51 36.84  0.275043  2458491.8917   9.5  0.0009   45  Hya
TOI 00503.01  8 17 16.90  12 36 04.91  3.677469  2458492.0534   9.2  0.0034  110  Cnc
TOI 00522.01  8 18 24.67 -07 34 16.63  0.397554  2458491.7050   7.4  0.0001  102  Hya

August 2019 selection

OBJECT        RA          DE           PERIOD(d)  EPOCH        mag_T  DEPTH  DURATION Const. 
                                                               (mag)  (mag)  (min)    IAU-Abbr
----------------------------------------------------------------------------------------------
TOI 00392.01  3  7 43.60  00 51 40.72   0.84907  2458411.5990   8.3  0.0179   81      Cet 
TOI 00394.01  3 13 59.89 -08 34 24.84   0.39149  2458411.2695   8.0  0.0005   44      Eri 
TOI 00554.01  4  2 59.51  09 12 30.60  7.048602  2458442.6193   6.4  0.0003  197      Tau 
TOI 00428.01  4 47 14.47 -17 14 54.10   0.63324  2458438.2958   7.8  0.0004   27      Eri 
TOI 00887.01  6 18 10.88  15 57 07.82   5.77114  2458472.0775   8.2  0.0018  167      Ori 


TOI 00547.01  6 48 19.17  -03 06 07.73  1.509017  2458469.0676  13.0  0.0221  148  <=== This is CoRoT-1b as a check

Selected transit-ephemerides for observing spots

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