If the surface of a star is as cool as the surface of the Sun (about 5800 K) or cooler, most of the atoms are in the ground state. ... Again, there are very few hydrogen atoms with electrons in the second energy level , so the Balmer lines of these stars are weak.
Why do a type stars have strong hydrogen absorption lines?
For stars with just the right surface temperature such that collisions continuously populate the first excited state with electrons, there will be lots of photons caught that excite the electrons to the second excited level , and there will be strong hydrogen absorption lines.
Why do O and B type stars have weaker hydrogen absorption lines?
So, most of the electrons in hydrogen are stuck on the ground orbit because they cannot absorb the lower energy light. This results in weaker absorption lines, because very few hydrogen atoms are participating . You cannot measure the temperature of the star based only upon its hydrogen line
Why do you stars exhibit weak hydrogen absorption lines?
G stars are too cool to excite hydrogen atoms to the first energy level from which they can then visible wavelengths of light. ... Why do O stars exhibit weak hydrogen absorption lines? At these high temperatures, nearly all the hydrogen is ionized, and is therefore unable to interact with light .
Why do stars of spectral types O and B show few absorption lines?
Why do stars of spectral types O and B show few absorption lines? Many atoms in these stars are ionized-have lost electrons-so can’t absorb . ... Photographs make brighter stars appear larger than fainter stars, although they should all be points of light.
Which star has the strongest hydrogen Balmer series absorption lines?
| Luminosity Class Star | VI Subdwarf |
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What temperature has the strongest Balmer lines?
In stars, the Balmer lines are usually seen in absorption, and they are “strongest” in stars with a surface temperature of about 10,000 kelvins (spectral type A).
What is the strongest hydrogen absorption line?
Temperature and Absorption Lines
“ A” stars have the strongest hydrogen lines. “O” stars are the hottest stars. “K” and “M” stars are the coolest stars. The strength of the absorption lines are temperature dependent.
Which color star is hottest?
White stars are hotter than red and yellow. Blue stars are the hottest stars of all.
What are the 7 spectral classes of stars?
The spectra of stars are described in terms of spectral classes. In order of decreasing temperature, these spectral classes are O, B, A, F, G, K, M, L, T, and Y . These are further divided into subclasses numbered from 0 to 9.
Which of the following is a valid way of demonstrating parallax for yourself?
Which of the following is a valid way of demonstrating parallax for yourself? Hold up your hand in front of your face, and alternately close your left and right eyes .
Why are Balmer lines weaker in hotter and cooler stars?
-H (Balmer) lines are weak because they are ionized . ... -In hotter stars, the hydrogen is being ionized, and things are so hot there is so much collision of atoms, photons, etc., if you strip away an electron, there is nothing left to give you any absorption.
What determines a star’s lifespan?
A star’s life cycle is determined by its mass . The larger its mass, the shorter its life cycle. ... When the hydrogen supply in the core begins to run out, and the star is no longer generating heat by nuclear fusion, the core becomes unstable and contracts.
Which spectral type has the weakest hydrogen lines?
Spectral Types. Stars are divided into groups called spectral types (also called spectral classes) which are based on the strength of the hydrogen absorption lines. The A- type stars have the strongest (darkest) hydrogen lines, B-type next strongest, F-type next, etc.
What is the hottest star type?
The spectral sequence is also a colour sequence: the O- and B-type stars are intrinsically the bluest and hottest; the M-, R-, N-, and S-type stars are the reddest and coolest.
What type of visible stars is the coolest?
A red star is the coolest, but still is about 5,000° Fahrenheit! Our sun is yellowish-white and the surface is about 10,000° Fahrenheit. The hottest stars are blue, and can be as hot as 200,000,000° Fahrenheit at their core!
