Objects in high res images of Lasco C3

[saisai]

At https://soho.nascom.nasa.gov/data/Theater/ when you use the highest resolution and pick a period of time, for example last week, and play the stuff slowly in 1fps or manually, there seems to be a lot of activity going on in there in the background. Considering SOHO is at L1 point - what are all those things flying around there considered to be? Shiny asteroids with interesting trajectories? There's also plentiful of static ones that are always gone in the next picture and they don't seem to follow a pattern, as in each picture is vastly different from the previous and the next one with nothing connecting them, though it could be noticeable if it updated more often than once every 12mins with seemingly quite a pause between the shots. Also what's causing the steady black distortion from the Sun towards upper right from a technical point of view?

for example https://imgur.com/wriCxkh

Edited September 28, 2022 by saisai

[Vancanneyt Sander]

those are protons that hit the CCD sensor and create these streaks accross the image. During SEP events these particles slamming into the sensor are getting more worse as you can see on the following image:

Proton levels the last few weeks are slightly elevated creating an increase in protons slamming into the instrument.

The black part in the image is an arm that's in front of the image sensor that holds the circular disk that occults the solar disk to be able to see the solar corona.

[saisai]

Thank you, that clarifies things!  makes sense now (a little bit, maybe)

Edited September 28, 2022 by saisai

[farm24]

also if you are ever unsure about if somethings an object or not, https://sungrazer.nrl.navy.mil/transits this site contains the Lasco transits that are predicted for the year

[Solarflaretracker200]

2 hours ago, Vancanneyt Sander said:

The black part in the image is an arm that's in front of the image sensor that holds the circular disk that occults the solar disk to be able to see the solar corona.

So that’s what that is. I always wondered but kept forgetting to ask 😂 

[CMEHunter]

2 hours ago, Solarflaretracker200 said:

So that’s what that is. I always wondered but kept forgetting to ask 😂 

Same!😁

[saisai]

https://imgur.com/MNzuyFS
So for example this one that goes through the occulter arm - what kind of distance does the sensor pick these very tiny particles up from? Do they have to physically hit the sensor? And how do the particles travel - in a wave-like pattern emanating from the Sun, or randomly from everywhere as it looks like in the more busy SEP event picture? I should likely just pick up some book and study the properties of light travel from somewhere, sorry to bother but the anomalies look fascinating to a layman 

[Vancanneyt Sander]

The LASCO instrument on board SOHO is exposed to space, to be able to photograph the Sun, the camera is exposed directly towards the Sun. So solar protons can hit it directly.

the arm holding the occulting disk is the external occulter, there’s also an internal one. As the arm is external, particles that slam into the instrument can still cause a streak through the shade of the external arm

when a proton hits, it hits the CCD imaging sensor. Each streak is a proton hitting it.
during SEP events on the Sun, these solar protons are emitted from the solar flare into outer space, they travel along the Parker spiral and the CME. Even a strong solar flare with SEP event on the far side can create elevated proton levels or SEP event on Earth! During the solar flare they can get accelerated so fast that they can already arrive 30 minutes after the flare. Do note that SEP events are not that common and only associated with strong long duration solar Flares.