The PLATO-Venus-Test

Motto: From Mercury's orbital period to 240 days

The goal

Confirm planets in orbit around stars other then the Sun with periods beyond Venus (225 days) by small telescope photometry of their transits.

This aims to test the detectibility of the signals of long (> 6h) and rare (less then 8 to less then 2 per year) transits of planets with orbital properties resembling those in the Solar System.

Thus approaching the confirmation of planets with 1 year orbits that are the goal of the PLATO mission - launch at end 2026.

The next transit-appointments

Events for TOI-Transits

• Venustest transits for Prague,

Selected known long period transiting planets

Known planets with transit periods 120-240d

• HIP 41378 e transits in ETD (131 d)
• Kepler-1514 b transits in ETD (218 d)
• Kepler-289 c transits in ETD (125 d)

What is needed

High precision differential photometry of the target star and the nearby stars over a period covering the event - ingress/egress/center - and at least one hour before and after the event in order to well characterise the before/after levels.

The goal is not a full lightcurve, but a detection of the transit event and possibly a confirmation of its expected properties. That means to collect evidence that the transit is occuring with the expected parameters at high confidence levels. That includes distinction from random (noise) and systematic (contaminants, weather photometric stability) errors.

Recommended equipment / experience:

• Telescope >20 cm diameter and >50cm focal lenght;
• Equatorial mount/drive;
• Detector/Camera (CCD/CMOS) with 1° field of view;
• Identification of stars brighter than 13^th mag_V;
• Image series photometry software – MUNIVIN, Siril, Astroimagej.

Transiting planets of bright stars, TESS and PLATO

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.

PLATO has a total light collection power slightly larger than NASA's Kepler. But the innovative optical segmentation concept (distribution of light-collection over 2+24 telescopes) allows ist to be applied to a large number of bright stars and thus, for the first time high accuracy determination of stellar properties including ages and an accurate determination of planetary masses for entire systems and planets in the terretrial regime - an Earth mass in Earth-sized orbit around a solar masss star.

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?

The TOI-candidates (TOI = TESS Object of Interest) 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.

Impressum und Datenschutzerklärung: Verein Kuffner-Sternwarte, 2024-10-21, Ephemerides updated; GW 2024-10-21, GW