Dr. Allan Sacha Brun

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Dr. Allan Sacha Brun

Dr. Allan Sacha Brun

@ASachaBrun

I am an astrophysicist, director of research at @CEA_officiel, expert of the Sun, stars and their impacts on (exo)planets @CEAIRFU @INSU_CNRS

Beigetreten Şubat 2020
47 Folgt161 Follower
Dr. Allan Sacha Brun retweetet
ESA Operations
ESA Operations@esaoperations·
Flyby success! @ESASolarOrbiter swept past Venus last night, using the planet's gravity to adjust its orbit and grant it a new view of the Sun's polar regions. Everything went as planned 🕹️🛰️✅
ESA Operations@esaoperations

ESA mission control will guide @ESASolarOrbiter through a close encounter with Venus tonight. The gravity assist manouevre will 'tilt' the spacecraft's orbit around the Sun and grant it a unique view of our star's enigmatic polar regions. 🕵️‍♀️ ☀️ esa.int/Enabling_Suppo…

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Dr. Allan Sacha Brun retweetet
ARCHIVED - NASA Sun & Space
Parker Solar Probe has made history. After seven days of silence, Parker has resumed communication with Earth, confirming it's healthy after soaring just 3.8 million miles from the solar surface — the closest a human-made object has ever been to a star. go.nasa.gov/40cucNU
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Dr. Allan Sacha Brun@ASachaBrun·
Very nice collaborative work masterly led by Valeriy on the occurrence of superflares in solar-type stars, in this busy solar activity year it is quite timely. Superflares once per Century mps.mpg.de/superflares-on…
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Dr. Allan Sacha Brun@ASachaBrun·
Great Whole Sun workshop at IAC, Big thank you to Valentin, Fernando, Daniel, Ernest and the solar team. Looking forward to Whole Sun @ IPa next March 3-21 2025.
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Dr. Allan Sacha Brun@ASachaBrun·
@slyardley yes I agree, @SolarOrbiter saw a bigger flare on the far side last May 2024. Let’s agree the recent X9 is the biggest on the dayside as of today. It is quite interesting to see how active the Sun’s southern hemisphere has become over the last weeks, pushing up the sunspot number.
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SolarSteph 🌞
SolarSteph 🌞@slyardley·
Keeping an eye 👀 on AR 3842 as it just produced an X9 flare with an associated eruption that is Earth-directed. It is one of the largest flares so far this solar cycle. For context AR3664 in May 2024 produced an >X12 on the farside that was detected by Solar Orbiter 🌞 🛰️
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Dr. Allan Sacha Brun retweetet
ESA Technology
ESA Technology@ESA_Tech·
📽️Europe's eclipse-making double-satellite mission Proba-3 has a 29 November launch date! Watch to learn about the mission set to open up new views of our Sun's surrounding atmosphere esa.int/ESA_Multimedia…
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Dr. Allan Sacha Brun retweetet
ESA Space Transport
ESA Space Transport@ESA_transport·
#Ariane6 first flight: Phase 2 complete! 2️⃣✅🎉 With the reignition of the upper stage & deployment of all CubeSats, Ariane 6 has completed it mission. This 2nd phase of the first flight consists of events 6 to 9 in this infographic: Ariane 6 has proven its brand new upper stage reignites in orbit and can deploy multiple varied missions into orbit.
ESA Space Transport tweet media
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Dr. Allan Sacha Brun@ASachaBrun·
So happy with the selection of JEDI and to be part of the adventure. Congratulations to Don and the whole JEDI team for a fantastic job. Even more fun and top space weather science to come with JEDI instrument and Vigil mission, looking forward to it.
NASA@NASA

Studying the Light Side with JEDI 🌞 We've selected the Joint EUV coronal Diagnostic Investigation (JEDI) to travel through space on @esa's upcoming Vigil mission. JEDI will capture images of the Sun in extreme ultraviolet light: go.nasa.gov/3URuaHl

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Dr. Allan Sacha Brun@ASachaBrun·
So many X flares, the Sun is making quite a show! Beautiful show also on Earth, with bright Aurorae all the way to southern France. Here, a movie of the last 48 hours of the Sun, quite impressive.
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Dr. Allan Sacha Brun retweetet
@mathewjowens.bsky.social
@mathewjowens.bsky.social@mathewjowens·
It is a *mess* out there.
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Dr. Allan Sacha Brun@ASachaBrun·
What an active Sun over the last 24-48h. We just got a X4.5 flare after many M7-9 and several X…
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Dr. Allan Sacha Brun@ASachaBrun·
Great total solar eclipse in Texas, beautiful prominence on the bottom right and complex corona as we near maximum of solar cycle 25. thx to colleagues (Eric and Aditi) for sharing their beautiful pictures with me ☀️
Dr. Allan Sacha Brun tweet mediaDr. Allan Sacha Brun tweet media
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Dr. Allan Sacha Brun retweetet
ESA Operations
ESA Operations@esaoperations·
AR 3590 will become increasingly magnetically connected with Earth. Any 'Energetic Solar Particles' following the magnetic field lines stretching out from the Sun are likely to impact Earth and satellites in orbit. Info and updates at: twitter.com/esaspaceweathe…
ESA Space Weather@esaspaceweather

❗️Strongest flare of solar cycle 25❗️ ✨X6.3✨ ⭕️Peak 22 Feb 22:34 UTC ⭕️Origin NOAA AR 3590 This AR is making itself known with 3 X-class flares in the last 36 hrs! We'll be keeping an eye on it as rotates towards the centre of the 🌞disk👀 🌐swe.ssa.esa.int/current-space-…

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Dr. Allan Sacha Brun retweetet
ESA Operations
ESA Operations@esaoperations·
A highly active region of the Sun recently fired off three of the strongest type of solar flare (X-class). The largest, an ‘X6.3’ flare released at 23:43 CET last night was the strongest solar flare observed during the current solar cycle. #SolarFlare #SpaceWeather
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Dr. Allan Sacha Brun retweetet
@travis-metcalfe.bsky.social
@travis-metcalfe.bsky.social@travis_metcalfe·
Interesting new analysis of Sun-like dynamo simulations, showing a minimum of the magnetic field slightly above the solar Rossby number! Note that Weakened Magnetic Braking appears to halt the rotational evolution *before* stars reach the bottom of the "V" arxiv.org/abs/2401.14460
@travis-metcalfe.bsky.social tweet media
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@adamfinley.bsky.social
@adamfinley.bsky.social@AdamF_Astro·
A good occasion to look where we are in the Sun's magnetic activity cycle? Here I compare the current sunspot cycle (25) to the last two: cycle 23 from 1996-2008, and 24 from 2008-2019. This cycle may have a similar shape, peaking in 2023 and again in 2025? Only time will tell!
@adamfinley.bsky.social tweet media
@adamfinley.bsky.social@AdamF_Astro

New Paper Day!! Are we able to estimate the magnetic field generation inside stars like the Sun using only measurements of their surface magnetism and differential rotation? We test one such hypothesis with a global convective dynamo simulation! arxiv.org/abs/2401.10984 (1/6)

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Dr. Allan Sacha Brun@ASachaBrun·
Solar-type magnetism vs time, a new story is emerging, with possibly a minimum of activity near solar (on convection and rotation) conditions. Read more on this interesting outcome published by @Qnorastraz - arxiv.org/pdf/2401.14460…
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Dr. Allan Sacha Brun retweetet
Horizon Magazine
Horizon Magazine@HorizonMagEU·
Researchers attempt to shed light on the Sun to trace its origins and ours. Read more ➡️ bit.ly/3JWHswK #HorizonEU
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