Bedlasky

When I was going to work yesterday (around 5:30 CET), I noticed some very bright object in the west. I was really confused what it might be, Saturn was under horizon by that time and that mysterious object was definitely brighter than Saturn. After a while I noticed that object is moving. I quickly grabed a phone and look in to the Stellarium what it is. It was ISS with -1,69 mag at that time. I never saw ISS before, so it was exciting event for me that morning.

Thanks!

That's exactly it! Here's picture from Stellarium for today's night:

Hello! I am a starting astronomer. I started with astronomy during my world-building project, because I needed to understand how everything in universe work and I really start liking it. It's nice to look at stars at night and just observe. Recently I was looking at Jupiter and Saturn with Celestrone LT70 at my parents house, I never saw planets in detail with my own eyes. I live in a city with big light polution, so I usually don't see much at night sky.

A weak ago I was looking at Jupiter and Galilean moons and between Callisto and Io there was a blue star Sigma Arietis. It looked like Jupiter have not 4 but 5 large moons :D. Sigma Arietis have apparent magnitude 5,52, so pretty much the same magnitude as Galilean moons. Really interesting sight.

Hello! I am working on my world-building project and I am making science-based world. I am trying to be realistic in my world-building. I have a binary star system with several planets, my "home" world orbits bigger star on S-type orbit. There are several planets with large moons in relatively close distance from my home world. I want to know if those planets and moons are distinguishable on the night sky by naked eye. I calculated planet-moon separations in angular diameter and apparent magnitudes. Here are my candidates for possibly observable moons (I didn't choose names for planets and stars yet, so for now I use just generic names): δ - Planet-moon separation as angular diameter (in arcminutes) m - apparent magnitude AcI: δ = 27,81' ; m = -3,1 AeI: δ = 80,01' ; m = -2,95 AfI: δ = 35,84' ; m = -0,22 AhI: δ = 8,98' ; m = 5,78 AhII: δ = 11,77' ; m = 5,05 AhIII: δ = 18,68' ; m = 4,43 AhIV: δ = 29,66' ; m = 3,44 There are also three candidates which could be maybe observable on a clean moonless sky with very low light polution: AhV: δ = 45,12 ; m = 6,79 AhVI: δ = 52,92 ; m = 6,97 AiIV: δ = 6,73 ; m = 7,92 Planet apparent magnitudes are: Ac: m = -8,62 Ae: m = -6,08 Af: m = -5,75 Ah: m = -3,3 Ai = 0,97 I know that average angular resolution of human eye is 1 arcminute, all of these moons have high enough separation to be distinguishable (in theory). But big role also plays apparent magnitude of the planet. The planet could be so bright that it outshine them. I searched some relation between magnitude and angular resolution, but I didn't found anything. Moons AhI-IV have quite similar values to Galilean moons, which usually cannot be seen by naked eye (I know that Callisto and Ganymede can be seen by people with very good eyes on clear sky with low light pollution). So my question is, how can I tell that certain moon is visible by naked eye and that planet wouldn't outshine it? Is there some calculation or chart which would generalize this for any moon?