Just adding to this, you should also label each image (we include Telescope, Wavelength, Date if important, and for the non-obvious images, we include a description. By non-obvious I mean like the supernovae inside a DSO.)syo_astro wrote: As for images, yes, all the images (they're pretty too!). Hope this helps, please keep questions coming if that was confusing!
Astronomy C
- PM2017
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Re: Astronomy C
West High '19
UC Berkeley '23
Go Bears!
UC Berkeley '23
Go Bears!
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Re: Astronomy C
Your question is a little unclear. What sort of reference values are you looking for?GarethM wrote:What reference value should be used for apparent/absolute visual magnitude? I can find luminosities for all wavelengths, but not just visible wavelengths.
Re: Astronomy C
I’ve seen questions that ask to convert absolute visual magnitude to visible luminosity measured in watts. I understand that a decrease in 5 magnitudes is a 100x increase in brightness, but I don’t understand what that increase is measured from, i.e. what value is defined as 0 on the magnitude scale. I was thinking I could measure relative to a star with a known absolute magnitude and visible luminosity, but I can’t find information on the visible luminosity of any stars. I’ve found info on bolometric magnitudes for all wavelengths, but nothing for just visible.
I’m basically wondering how to calculate visible luminosity in watts when given absolute visible magnitude.
I’m basically wondering how to calculate visible luminosity in watts when given absolute visible magnitude.
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Re: Astronomy C
My typical method is to take the Sun's absolute magnitude of around 4.85 and use its known luminosity in watts to convert.GarethM wrote:I’ve seen questions that ask to convert absolute visual magnitude to visible luminosity measured in watts. I understand that a decrease in 5 magnitudes is a 100x increase in brightness, but I don’t understand what that increase is measured from, i.e. what value is defined as 0 on the magnitude scale. I was thinking I could measure relative to a star with a known absolute magnitude and visible luminosity, but I can’t find information on the visible luminosity of any stars. I’ve found info on bolometric magnitudes for all wavelengths, but nothing for just visible.
I’m basically wondering how to calculate visible luminosity in watts when given absolute visible magnitude.
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Re: Astronomy C
I do this as well.Unome wrote:My typical method is to take the Sun's absolute magnitude of around 4.85 and use its known luminosity in watts to convert.GarethM wrote:I’ve seen questions that ask to convert absolute visual magnitude to visible luminosity measured in watts. I understand that a decrease in 5 magnitudes is a 100x increase in brightness, but I don’t understand what that increase is measured from, i.e. what value is defined as 0 on the magnitude scale. I was thinking I could measure relative to a star with a known absolute magnitude and visible luminosity, but I can’t find information on the visible luminosity of any stars. I’ve found info on bolometric magnitudes for all wavelengths, but nothing for just visible.
I’m basically wondering how to calculate visible luminosity in watts when given absolute visible magnitude.
West High '19
UC Berkeley '23
Go Bears!
UC Berkeley '23
Go Bears!
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Re: Astronomy C
It definitely will be an event next year, and I'm not sure but I think the topic will be variable stars or star/planet formation.jz123sst wrote:Does anyone know if Astronomy will still be an event 2019-2020 (next year)? If so, what topics will it cover?
West Windsor-Plainsboro High School South '21
2021 Nationals: Astronomy - 1st, Geologic Mapping - 1st, Team - 6th
2021 Nationals: Astronomy - 1st, Geologic Mapping - 1st, Team - 6th
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Re: Astronomy C
Yes... like there is a 99.9% chance I would say.jz123sst wrote:So stellar evolution is a topic every year?
West Windsor-Plainsboro High School South '21
2021 Nationals: Astronomy - 1st, Geologic Mapping - 1st, Team - 6th
2021 Nationals: Astronomy - 1st, Geologic Mapping - 1st, Team - 6th
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