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Vol. 643
10. Planets and planetary systems MIRACLES: atmospheric characterization of directly imaged planets and substellar companions at 4-5 μm. II. Constraints on the mass and radius of the enshrouded planet PDS 70 b by T. Stolker, G.-D. Marleau, G. Cugno, et al., 2020, A&A, 643, A13 The young (~5 Myr) T Tauri star PDS 70 is an emblematic object for the study of planetary formation. It holds a gapped circumstellar disk in which two embedded planets (PDS 70 b and c) have been directly imaged and show evidence for gas accretion through detection of H alpha emission. The atmospheric and circumplanetary characteristics of these accreting young planets remain poorly understood, and a previous study of the spectral energy distribution of PDS 70 b has suggested a possible combination of emission from a planet atmosphere and a circumplanetary disk. Using VLT/NACO, Stolker et al. report the first detection of PDS 70 b in the Brα and M' filters as well as a tentative detection of PDS 70 c in Brα. PDS 70 b appears significantly redder than any previously imaged planets and brown dwarfs in the color (K-M') - magnitude (M') diagram. Fitting the resulting 1-5 um spectral energy distribution leads to a photospheric temperature Teff = 1193 +/- 20 K and a photospheric radius R = 3.0 +/- 0.2 R_J. In addition, by comparing the object's luminosity with predictions from planet structure models, and taking into account the accretion luminosity as constrained by H alpha, the authors were able to constrain the mass of PDS 70 b to Mp ≈ 0.5–1.5 M_J and its physical radius to Rp ≈ 1–2.5 R_J. The discrepancy between the photospheric and planetary radii may indicate that the planet is embedded in an extended dusty environment, muting molecular features in the object's spectrum, which implies that PDS 70 b not only accretes gas but is also continuously replenished by dust.

Innovative solutions to urban planning will be explored at an online seminar to be held on Thursday 26 November.

The ESAIL microsatellite for tracking ships at sea has captured 57 000 messages in its first 24 hours of operation, using advanced on-board processing algorithms.

You’re controlling your very own space agency at the dawn of the space age, with the ultimate goal of setting foot on the surface of Mars. Which technologies should you research? Which rockets should you build? Should you aim for the Moon first or head straight to the Red Planet?

A tremendous explosion bursts out from the Sun. Just a few minutes later and the spacecraft is bathed in radiation, blinding the star trackers it relies on to know what direction it's pointing in. The spacecraft goes into Safe Mode, like a turtle retreating into its shell. Most units are powered off, the onboard computer is rebooted and spacecraft points its solar arrays to the Sun. The control teams are left wondering what on Earth – or in space – has gone wrong.

It was a difficult campaign to organise, but the scientific results are some of the best ever. Earlier this month, over 60 researchers ran 11 experiments in an Airbus aircraft with no less than three pilots. This was no ordinary flight: the A310 'Air Zero G' flew in repeated arcs 600 m up and down, providing ‘weightlessness’ in freefall conditions for all passengers and their experiments, 20 seconds at a time.

It was a difficult campaign to organise, but the scientific results are some of the best ever. Earlier this month, over 60 researchers ran 11 experiments in an Airbus aircraft with no less than three pilots. This was no ordinary flight: the A310 'Air Zero G' flew in repeated arcs 600 m up and down, providing ‘weightlessness’ in freefall conditions for all passengers and their experiments, 20 seconds at a time.

Press Release N° 26–2020 ESA is signing an €86 million contract with an industrial team led by the Swiss start-up ClearSpace SA to purchase a unique service: the first removal of an item of space debris from orbit. As a result, in 2025, ClearSpace SA will launch the first active debris removal mission, ClearSpace-1, which will rendezvous, capture and bring down for reentry a Vespa payload adapter. Journalists are invited to follow an online round table for media on Tuesday, 1 December, at 13:30 CET. Mission experts will give an overview of the project status, explain the ambitious mission design and detail the next steps leading to launch.

Authors: M. Tiwari, K. M. Menten, F. Wyrowski, A. Giannetti, M.-Y. Lee, W.-J. Kim and J. P. Pérez-Beaupuits.
Astronomy & Astrophysics Vol. 644 , page A25
Published online: 26/11/2020
Keywords: ISM: abundances ; ISM: molecules ; submillimeter: ISM ; stars: formation ; ISM: individual objects: M 8.

Authors: P. Ioannidis and J. H. M. M. Schmitt.
Astronomy & Astrophysics Vol. 644 , page A26
Published online: 26/11/2020
Keywords: stars: activity ; stars: rotation ; stars: flare ; starspots ; techniques: photometric ; methods: data analysis.