Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

solar prominences during totality

Eclipse Observing Astrometry
8 replies to this topic

#1 patrickmalone51

patrickmalone51

    Lift Off

  • -----
  • topic starter
  • Posts: 5
  • Joined: 13 Apr 2024

Posted 13 April 2024 - 11:44 AM

I'm attaching two photos I took during totality that show what looks to my amateur eye as big changes in the prominences over two minutes. Image 9429 (on the left in the thumbnails) was taken at 1:42:11 CDT in Plano Texas. You can see a small prominence at around 5:30 or 6 o'clock on the circle (plus some bigger prominences at the top). (Forgive my non-astronomer terminology.) Image 9619 was taken at 1:44:32. (Totality ended with the second diamond ring showing up nine seconds later.) I thought it was interesting how much bigger the prominence had gotten over those two minutes. Did others see the same thing? 

 

Also, query: How does one measure the size of these prominences? Knowing the sun is 865,000 miles in diameter, I guess you could eyeball it on these images but I'm sure there's a more precise way to do it.  

 

One way to do it might be to measure the pixel width of the sun compared to the pixel dimensions of these prominences. I'm pretty good with Lightroom but don't know how to use it to measure pixel dimensions in an image. 

 

Any guidance others can offer would be welcome. 

Attached Thumbnails

  • 20240408-_Z9A9429.jpg
  • 20240408-_Z9A9619.jpg

  • R Botero, PhotonHunter1, Lopper and 1 other like this

#2 Starry_Spruce

Starry_Spruce

    Vostok 1

  • *****
  • Posts: 179
  • Joined: 08 Oct 2023
  • Loc: Maine

Posted 13 April 2024 - 12:46 PM

Nice images.

 

The big reason you see change is because the moon is moving, and thus covering more or less of them as it moves across the disk of the sun. 


Edited by Starry_Spruce, 13 April 2024 - 12:47 PM.

  • SkipW, geovermont, Lopper and 1 other like this

#3 patrickmalone51

patrickmalone51

    Lift Off

  • -----
  • topic starter
  • Posts: 5
  • Joined: 13 Apr 2024

Posted 13 April 2024 - 05:00 PM

thanks for that. My remaining question is the size of these prominences. I did a rough pixel measurement of the south pole prominence on the second image here and it looks to be roughly 80 pixels on each side compared to 1,800 pixel diameter of the sun itself. (I'm attaching a very tight crop on that southerly prominence.)  that would make it around 37,000 miles across. calculating the areas and comparing to the size of the earth (7,900 mile diameter), it looks like you could fit about 23 earths into this prominence on the south side of the photo. I hope that's right but if I'm wrong, please correct me. 

Attached Thumbnails

  • PMalone-2-118.jpg


#4 Special Ed

Special Ed

    Hubble

  • *****
  • Posts: 12,741
  • Joined: 18 May 2003
  • Loc: Greenbrier County, WV 38N, 80W

Posted 14 April 2024 - 01:04 PM

Those are nice images.  smile.gif

 

I think 23 Earths into that prom is high.  Take a look at today's SOHO WL image--it has Earth to scale at the bottom right.

 

mdi_sunspots_1024.jpg



#5 kfiscus

kfiscus

    Cosmos

  • *****
  • Posts: 8,247
  • Joined: 09 Jul 2012
  • Loc: Albert Lea, MN, USA

Posted 14 April 2024 - 02:07 PM

I did some crude measurements right off of my laptop screen.  I got a solar diameter of about 4-15/16" and a prominence height of 3/16".  That got me a height of about 33,000 miles for the gorgeous, showstopping prom.  (A little over 4 Earths tall.)

 

EDIT  This probably doesn't do justice to that prominence.  My solar diameter was really the lunar diameter on the screen.  You could add a few thousand more miles.


Edited by kfiscus, 14 April 2024 - 02:18 PM.


#6 patrickmalone51

patrickmalone51

    Lift Off

  • -----
  • topic starter
  • Posts: 5
  • Joined: 13 Apr 2024

Posted 14 April 2024 - 02:43 PM

Thanks Ken Fiscus. that's similar to measurements i got from Lightroom with pixels.  4-5 earths tall and 4-5 earths wide gets you to the 23 I was thinking of earlier. but who knows, maybe it's only 10-15 earth sizes. still pretty huge. 



#7 DrkNite

DrkNite

    Sputnik

  • -----
  • Posts: 43
  • Joined: 25 Jul 2006

Posted 15 April 2024 - 08:10 AM

Here are 2 images from the Solar Dynamics Observatory showing the prominences around the time of totality.  It's nice to be able to see how the features look compared to the observations here on the ground.

 

 

 

Attached Thumbnails

  • 20240408_190842_512_0304.jpg
  • 20240408_190546_512_0171.jpg


#8 patrickmalone51

patrickmalone51

    Lift Off

  • -----
  • topic starter
  • Posts: 5
  • Joined: 13 Apr 2024

Posted 15 April 2024 - 08:29 AM

thanks for those images, very good to compare. The triangular prominence at about 4 o'clock in these images looks to be the same that I was looking at, at about 5:30.



#9 dizzydlz

dizzydlz

    Lift Off

  • -----
  • Posts: 12
  • Joined: 06 Feb 2024

Posted 15 April 2024 - 08:55 AM

I made a scale earth using pixel counts to make this image from one of my photos near C2. I figured it takes close to 109 earth diameters to cross the sun so the row of 55 earths is close to the halfway point. Note the earth image placed inside a "leaping" C2 prominence on the left side of the picture for an idea of size. around 4 earth diameters beyond the sun surface. 

Earth And Flare compare




Reply to this topic



  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics





Also tagged with one or more of these keywords: Eclipse, Observing, Astrometry



Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics