Why Do We Use Angular Size Instead of Steradian for Objects in the Night Sky?

  • Thread starter Thread starter 4everphysics
  • Start date Start date
  • Tags Tags
    Angular
4everphysics
Messages
19
Reaction score
0
When we measure the angle that certain object subtends in the night sky,
why do we commonly use angular size instead of steradian?
 
Astronomy news on Phys.org
If the object is circular, it simplifies things.
 

Thread '3I/ATLAS, Interstellar Comet'

3I/ATLAS, also known as C/2025 N1 (ATLAS) and formerly designated as A11pl3Z, is an iinterstellar comet. It was discovered by the Asteroid Terrestrial-impact Last Alert System (ATLAS) station at Río Hurtado, Chile on 1 July 2025. Note: it was mentioned (as A11pl3Z) by DaveE in a new member's introductory thread. https://www.physicsforums.com/threads/brian-cox-lead-me-here.1081670/post-7274146 https://earthsky.org/space/new-interstellar-object-candidate-heading-toward-the-sun-a11pl3z/ One...
View full post »

Thread 'How feasible is home radio astronomy?'

Is a homemade radio telescope realistic? There seems to be a confluence of multiple technologies that makes the situation better than when I was a wee lad: software-defined radio (SDR), the easy availability of satellite dishes, surveillance drives, and fast CPUs. Let's take a step back - it is trivial to see the sun in radio. An old analog TV, a set of "rabbit ears" antenna, and you're good to go. Point the antenna at the sun (i.e. the ears are perpendicular to it) and there is...
View full post »

Similar threads

I What is the correct way to calculate the area of the sky in square degrees?
Replies
11
Views
4K
I A busy and interesting night sky in Mackinaw City
Replies
1
Views
2K
I How Does Angular Diameter Distance Apply to the Last Scattering Surface?
Replies
2
Views
2K
I Lines of stars that we see in the sky
Replies
26
Views
5K
I Why is Mercury Visible at Night?
Replies
18
Views
11K
Stargazing The Pleiades: an underrated glory of the night sky
Replies
9
Views
3K
How Far Can We Detect Faint Celestial Objects Near Our Solar System?
Replies
6
Views
2K
How much of the night sky one could see from various locations
Replies
9
Views
12K
Stargazing Can distance in space be measured by human systems?
Replies
22
Views
3K
B Do changes in speed always affect orbit size, and vice versa?
Replies
30
Views
3K

Hot Threads

Recent Insights

Back
Top