30
votes
Was Galileo expecting to see so many stars?
tl;dr: Probably yeah, Galileo was a smart guy and probably reasoned that if he could get a better view, he could see more stuff (like stars)
Consider what a night sky looks like with absolutely no ...
- 3,364
17
votes
Are main-sequence G9 stars habitable?
Stars themselves are not "habitable", but any star could have a "habitable zone". Generally the term "habitable zone" refers to the zone around a star in which water ...
- 104k
11
votes
Was Galileo expecting to see so many stars?
Hans Lippershey made the first practical telescope in 1608 and based on it, Galileo made his own telescope in the following year having 3x magnification which he later improved to 30x magnification. ...
- 3,780
5
votes
Can stars be born giants?
You seem to be mixing up red giants, a late stage in the life cycle of most stars, and giant stars in general, which are any stars with particularly large radius and luminosity.
Stars larger than ...
5
votes
How certain is the Sun's classification?
Formally the spectral type of a star is defined by the type of dark lines in the spectrum. G-type stars have prominent lines from singly ionised calcium in their (ultraviolet) spectrum. These are the ...
- 104k
4
votes
Are main-sequence G9 stars habitable?
Another way to find the limits of the habitable zone of a star is to find the ratio between the star's luminosity and that of the Sun. Some sources give the luminosity of a star in units of solar ...
- 6,572
3
votes
In layman's terms, why does the cold C-N-O process end in Carbon?
Both 15N($p,\alpha$)12C and 15N($p,\gamma$)16O can and do take place. However, the former is a strong force interaction, whilst the latter is mediated by the electromagnetic force and is known as a &...
- 132k
3
votes
Can stars be born giants?
It depends what you mean by "born". If by "born" you mean commence nuclear fusion of hydrogen, then all stars are "born" on the main sequence as hydrogen burning stars ...
- 132k
2
votes
In layman's terms, why does the cold C-N-O process end in Carbon?
This question has several misunderstandings.
The CNO cycles (there is more than one CNO cycle) in a main sequence star have nothing to do with the triple alpha process. A star that is using the triple ...
- 32.1k
2
votes
What is a dM1e red dwarf star? What do the '1' and 'e', specifically, stand for?
The 9 main spectral types (the classical OBAFGKM ones plus the more recent L and T ones for brown dwarfs) indicate the general features seen in the spectra and are in descending of temperature (O is ...
- 7,718
1
vote
Accepted
Adhara ultraviolet magnitude
Those making the claims should define exactly what they mean.
U-band magnitudes are well defined. The Johnson U-band covers from about 300-400 nm with a peak at 360 nm. The peak wavelength would be ...
- 132k
1
vote
Can stars be born giants?
The answer literally depends on which direction you look. Some "dwarfs" born on the main sequence could be as big as "giants" that have evolved off it.
Wikipedia reports that the ...
- 363
Only top scored, non community-wiki answers of a minimum length are eligible