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Dr Adam J. Finley @adamfinley.bsky.social · 14d

Comparison at the time of Orbiter:

Dr Adam J. Finley @adamfinley.bsky.social · 14d

Beautiful double erruption in 304A observed by GOES/SUVI and Solar Orbiter over the east-limb (slightly later) in the low-latency data.

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Reposted by Dr Adam J. Finley

ESA Space Science @science.esa.int · 23d

Are you an early-career scientist or engineer?

Then the ESA Research #Fellowships in Space Science might be just the right opportunity for you.

Check out the programme details here 👉 www.cosmos.esa.int/web/space-sc... 🔭 🧪 ☄️

Photograph of the bottom half of the Sun, with a highlighted square region around the Sun's south pole. Taken in ultraviolet light, the image shows the hot gas in the Sun's outer atmosphere, the corona, glowing yellow as it extends outwards in threads and loops from the Sun. Credit: ESA & NASA/Solar Orbiter/EUI Team, D. Berghmans (ROB)

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Dr Adam J. Finley @adamfinley.bsky.social · 28d

The Alfvén radius is linked to the solar wind mass and magnetic flux. The wind magnetisation parameter (~ratio of mag/mass flux), is used to understand this dependence. Our results follow the trends from MHD wind simulations, but had an offset that is likely due to 3D effects and turbulence. (5/8)

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Dr Adam J. Finley @adamfinley.bsky.social · 28d

Towards maximum activity, the heliospheric current sheet became complex and the solar wind sources moved towards the active latitudes. So, for example, an encounter of PSP that spends more time in the solar wind near current sheets will have a smaller Alfvén radii on average. (7/8)

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Dr Adam J. Finley @adamfinley.bsky.social · 28d

A very dipolar magnetic field became inclined to the rotation axis. (6/8)

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Dr Adam J. Finley @adamfinley.bsky.social · 28d

The heliospheric current sheet became warped by the emergence of active regions. (5/8)

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Dr Adam J. Finley @adamfinley.bsky.social · 28d

The evolution of the coronal magnetic field during the solar cycle, strongly influenced the magnetic connectivity of PSP. Each encounter is different, which obscures our perception of the average Alfvén radius. Near minimum, the wind measured by PSP originated closer to the Sun's poles. (4/8)

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Dr Adam J. Finley @adamfinley.bsky.social · 28d

We mapped the wind back to its source using the Parker spiral and a potential field source surface model. The Alfvén surface was modulated by structure in the corona. Smaller near current sheets and pseudo-streamers, larger near the dipole axis and expanding magnetic field. (3/8)

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Dr Adam J. Finley @adamfinley.bsky.social · 28d

Using hourly measurements from the SWEAP and FIELDS suites, we mapped PSP to the Alfvén surface with a Parker spiral. Each encounter had a distribution of radii. The longitudinal-average reduced the bias from individual wind streams, the average grew from 10-16 solar radii. (2/8)

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Dr Adam J. Finley @adamfinley.bsky.social · 28d

Side project day! NASA's Parker Solar Probe (PSP) has been exploring the near-Sun enviroment since the start of solar cycle 25. Now passing maximum activity, how has the shape and size of the Sun's Alfvén surface evolved since? arxiv.org/abs/2509.07088 (1/8)

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Dr Adam J. Finley @adamfinley.bsky.social · Sep 5

New paper day! Metcalfe et al. review the evidence for weakened magnetic braking around the Sun's age by homogenizing the stellar parameters from previous studies that constrained the wind braking of stars with observed magnetic fields and x-ray fluxes (proxy for mass-loss): arxiv.org/pdf/2509.03717

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Dr Adam J. Finley @adamfinley.bsky.social · Sep 2

3D view of this plot:

Dr Adam J. Finley @adamfinley.bsky.social · Sep 2

Approaching perihelion (16th Sept.), the structure of the coronal magnetic field is similar to our prediction from July. The Sun's dipole field remains fully inclined with nested active regions influencing the heliospheric current sheet. Solar Orbiter will be mostly connnected to active latitudes.

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Dr Adam J. Finley @adamfinley.bsky.social · Sep 2

ESA Solar Orbiter is zooming towards the Sun (perihelion at 0.29au on the 16th Sept.), currently at 0.44au the spacecraft has a nice view of the south pole (combined image from EUI/FSI). Coronal holes, filaments, active regions, lots of things to investigate!

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Reposted by Dr Adam J. Finley

ESA Space Science @science.esa.int · Sep 1

Our #SolarOrbiter has split the flood of energetic electrons flung out into space from the Sun into two groups, tracing each back to a different kind of outburst from our star 👉 www.esa.int/Science_Expl...
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Infographic showing how the Solar Orbiter spacecraft traces superfast electrons back to their sources on the Sun. The Sun is depicted on the left, with colored dots representing sources of energetic electrons from solar flares (blue) and coronal mass ejections (red). Curved lines illustrate magnetic field lines along which electrons travel from these events toward the Solar Orbiter spacecraft, shown on the right against a starry background. Text explains that more than 300 bursts of 'Solar Energetic Electrons' were observed between November 2020 and December 2022, allowing scientists to connect electrons detected in space with their origins on the Sun.

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Dr Adam J. Finley @adamfinley.bsky.social · Aug 28

ESA's Solar Orbiter @esa.int @science.esa.int has begun to sned data home again after it passed superior conjunction on the far-side of the Sun to Earth. With Solar Orbiter slightly below the solar equator and Earth slightly above, we get a nice 360 degree view of the solar surface. ☀️🔍👀

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Dr Adam J. Finley @adamfinley.bsky.social · Aug 28

Looking at this swirling feature in the solar atmosphere, revealed that the viscous heating along the swirl boundary was connected with the breakdown of coherent oscillations in the swirl. The MSF/W method provides a new pathway to investigate wave activity in the solar atmosphere. (4/4)

Dr Adam J. Finley @adamfinley.bsky.social · Aug 28

Using this approach, horizontal slices of a realistic solar atmosphere were decomposed into their most significant frequencies. A biproduct of this method, the highest frequency bin highlights dissipation/shocks. This is especially clear at swirl boundaries. (3/4)

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Dr Adam J. Finley @adamfinley.bsky.social · Aug 28

The MSF/W method uses discrete Fourier transforms to move variables into frequency/wavenumber space and identify the most significant contribution to that variable at a given time/place. An example of a signal decomposed into the most and 2nd most significant wavenumbers. (2/4)

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Dr Adam J. Finley @adamfinley.bsky.social · Aug 28

New paper day! 🔥 George Cherry et al. develop the Most Significant Frequency/Wavenumber method for detecting wave activity in realistic magnetohydrodynamic simulations of the Sun's atmosphere. Published in A&A: www.aanda.org/articles/aa/... (1/4)

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Reposted by Dr Adam J. Finley

ESA Space Science @science.esa.int · Aug 27

Are you an early-career scientist or engineer?

Then the ESA Research #Fellowships in Space Science might be just the right opportunity for you.

Check out the programme details here 👉 www.cosmos.esa.int/web/space-sc... 🔭 🧪 ☄️

Banner that reads: ESA SPACE-SCIENCE FELLOWSHIP PROGRAMME. Join us in the exciting adventure that is space science!

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Dr Adam J. Finley @adamfinley.bsky.social · Aug 15

Solar Orbiter Hackathon, 17–21 November 2025 at ESA/ESTEC (Noordwijk, NL).

20 ECRs (PhD and postdoc) will form 5 teams lead by mentors. This is a great chance to connect and collaborate on Solar Orbiter science!

For more information: www.cosmos.esa.int/web/solar-or...

Deadline to apply: 5th Sept.

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Dr Adam J. Finley @adamfinley.bsky.social · Aug 4

The magnetic energy in the quadrupole (l=2) and dipole (l=1) are now pretty comparable which may be why the solar corona is looking so dipolar. The octupole (l=3) is often in synch with the dipole and so the quadrupole is the main competitor when it comes to the large-scale structure.

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Dr Adam J. Finley @adamfinley.bsky.social · Jul 28

Two crossings of the coronal hole at the negative dipole axis at 310 Carrington longitude. Closest approach in the south above the coronal hole at 180 degree (which may have closed by then). And a scan across the nested active regions at (-15,120) and (15,20), if they stay active until September..

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