This is the spectroscopic transit of a #planet with an orbital period of 1.5 YEARS !! #HIP41378 🪐

In case you missed the great paper led by @sgrouffal (#ProudAdvisor), arXived over the summer, here is a recap'.

The planet HIP41378 f is a Saturn-sized transiting planet with an orbital period of 542 days. It means we can observe its transit only once every 1.5 years - it's actually once every 3 years from the ground as the host star is too close to the Sun (as seen from the Earth) every other transits.

With such a long orbital period and a nearly circular orbit, the transit event lasts 19 hours (!). Hence, from the ground, any observer could only observe a tiny fraction of the transit. To overcome this issue, back in 2022, we set up a worldwide collaboration of almost all high-resolution radial-velocity spectrographs across the globe. Over the same night, all the instruments observed the target HIP41378 at the time of planet'f transit, allowing us to detect the Rossiter-McLaughlin (RM) effect.

The RM effect is measuring the planet's orbital obliquity, i.e. the angle between the orbital plane and the spin axis of the star. While this angle is ~0º in the solar system, for HIP41378 it reaches Ψ=~52º.

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#Science #Space #Exoplanet #Astrophysics #Astronomy #telescope

2 weeks ago, we were observing the rare transit of the #exoplanet #HIP41378 f. It was one of the largest ground-based observing campaign on an exoplanet so far.

Today, we did our first #zoom call with the PIs (Principle Investigators) of the spectroscopic data, in order to decide the strategy for data reduction, analysis and #publication. Another zoom is schedule later this week for the photometric campaign.

The data are so great that we believe we have room for 4+ #papers.

#AstronomerLife

If you want to get some news on the #HIP41378 system that I observed last weekend, you shall follow @sgrouffal.

She is doing a #PhD thesis with me on the #PLATO space mission from the European #Space agency #ESA. She is also working on the analysis of exquisite data of #HIP41378 taken with the very large telescope #VLT, in #Chile.

She is also the artist who produced this great #video of the system 🤩

#Astronomy #Astrophysics

Wow, this campaign on #HIP41378 f has been incredible ! I can tell you it's a great success. I am receiving many emails from colleagues across the #world reporting me they managed to observe the #transit. Now will start the long process of reducing / analysing / publishing the data.

Stay tuned.

I hope you enjoyed being informed about this campaign.

Next rendez-vous with #HIP41378 is planned for early January, with the transit of planet d that will be observed by #CHEOPS 🛰️ .

#astronomy

📅 2022-11-13 22:36 UT

According to the best ephemeris, the forth contact of the #transit of #HIP41378 f should occur now.

#Astronomy

📅 2022-11-13 21:23 UT

According to the best ephemeris, the third contact of the #transit of #HIP41378 f should occur now.

#Astronomy