I am doing a GCSE Astronomy course, but it's not for school. It is a long distance learning course, and this is a question on one of the assignments.mfb said:What do you think?
Is this homework?
Thanks for moving it to the more specific section. The wavelength would get shorter. What do you mean about the digit?mfb said:I moved the thread to the homework section.
Does the wavelength get longer or shorter if the galaxy is moving towards us?
You might want to keep one more digit precision in the calculations.
But the wavelength you are given here gets longer.Atominate said:The wavelength would get shorter.
Your rounding is quite imprecise.Atominate said:What do you mean about the digit?
Right.Atominate said:I see, so the wavelength is increasing by 4.9nm meaning the Galaxy is moving away?
No, that is fine. The 0.01 relative shift you calculated is imprecise. There is a huge difference between 0.005 and 0.0149 (a factor of 3!) but both would get rounded to 0.01 if you just keep two digits after the decimal point.Atominate said:I've been told to consider the speed of light as 300,000km/s for this question. Is this what you mean about rounding?
I don't understand what you mean. I am not rounding any of the figures. Can you explain?mfb said:No, that is fine. The 0.01 relative shift you calculated is imprecise. There is a huge difference between 0.005 and 0.0149 (a factor of 3!) but both would get rounded to 0.01 if you just keep two digits after the decimal point.
Okay. Thanks for your help.mfb said:Ah I see, it happens to be "exactly" 0.01. I would still keep one more digit and write it as 0.010.
An absorption line is a dark line in a spectrum that indicates the absorption of light by a specific element or molecule. These lines are created when light passes through a material and certain wavelengths are absorbed, leaving a gap in the spectrum.
The wavelengths at which absorption lines appear are determined by the energy levels of the atoms or molecules in the material. Each element or molecule has a unique set of energy levels, so they will absorb light at specific wavelengths.
Astronomers use absorption lines to identify the chemical composition of stars and other celestial objects. By comparing the wavelengths of the absorption lines in a star's spectrum to known wavelengths for different elements, scientists can determine which elements are present in the star.
Yes, the widths and depths of absorption lines can provide information about the temperature of a star or galaxy. The amount of broadening or narrowing of an absorption line is related to the speed and temperature of the material that is absorbing the light.
There are a few possible causes for absorption lines to shift to different wavelengths. One is the Doppler effect, which occurs when a light source is moving towards or away from an observer. Another cause is the gravitational pull of a massive object, which can cause the wavelengths of light to stretch or compress. Finally, absorption lines can also be shifted by interactions with other particles, such as collisions or chemical reactions.