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Planet in a Globular

Posted: Fri May 02, 2014 8:37 pm
by geckzilla
I have taken pen to tablet and attempted my own version of this, which is a combination of a screenshot in Stellarium to give me an idea of visual magnitudes of stars and picture of NGC 2419 by Hubble. I tried to get the majority of stars to match Jupiter's brightness. The Milky Way is in the background but it is actually pretty hard to see with the cluster intervening. This is supposed to be a kind of naked-eye view but that is of course impossible to translate to a computer screen. Still, maybe it could be done better?
globular_simulation.jpg
Amusingly, the "moon illusion" seems to apply to the globular cluster which seems less impressive once it has risen above the horizon which I partially attribute to my guess at how it would look since there is less atmosphere to diffuse the glow.
globular_rising.jpg

Re: Planet in a Globular

Posted: Sat May 03, 2014 12:49 am
by BDanielMayfield
Interesting geck. How far out from the globular's center is your simulated planet?

Re: Planet in a Globular

Posted: Sat May 03, 2014 12:55 am
by geckzilla
Oh, I have no idea. It's at the outskirts of it somewhere. I'd have to do some math to answer that kind of question with any detail. I'd have to do some more math to give a reasonable approximation for how the sky would look for an Earth in the very core of the cluster.

Re: Planet in a Globular

Posted: Sat May 03, 2014 2:00 am
by BDanielMayfield
geckzilla wrote:Oh, I have no idea. It's at the outskirts of it somewhere. I'd have to do some math to answer that kind of question with any detail. I'd have to do some more math to give a reasonable approximation for how the sky would look for an Earth in the very core of the cluster.
Yeah, I like math, but have to be in the in mood, like when I don't have a headache already.

How to covert absolute magnitudes into apparent with known distances is something I should know. But I would guess that with many stars pealing off the main sequence into various states of giantdom in globulars there should be a great number of stars way brighter than what Jupiter ever appears to us.

Re: Planet in a Globular

Posted: Mon May 05, 2014 3:24 am
by Ann
Very interesting pictures.

You wrote:
The Milky Way is in the background but it is actually pretty hard to see with the cluster intervening.
If you lived inside a globular cluster, it would be easy to think that the cluster was the whole universe. Perhaps, if you lived inside a globular, you might sing with Peggy Lee about the universe:
Click to play embedded YouTube video.
Ann

Re: Planet in a Globular

Posted: Mon May 05, 2014 3:57 am
by geckzilla
We already did that even without a globular cluster in the way, though. The sky was the firmament and it was fixed and the Earth was all there was. It took a telescope and some clever thinking to figure out what the Milky Way was. Telescopes could still peer into the Milky Way from within a globular cluster easily enough, especially looking through the side of the sky not blocked by the cluster.