Filters - Revision history

Rebull: /* Other sources of interest */

2020-10-26T17:18:36Z

Other sources of interest

Rebull at 17:18, 26 October 2020

2020-10-26T17:18:06Z

Rebull at 19:01, 11 August 2020

2020-08-11T19:01:30Z

Rebull: Replaced content with " =Most coherent, developed, tested materials= *[https://www.youtube.com/watch?v=aYVEGkx0rUc&list=PLjCjDYabTFm9b9jQd4hcZPAnFWYsIjs2D&index=2&t=0s Movie (19:53) on Filters]..."

2020-07-31T22:49:19Z

Replaced content with " =Most coherent, developed, tested materials= *[https://www.youtube.com/watch?v=aYVEGkx0rUc&list=PLjCjDYabTFm9b9jQd4hcZPAnFWYsIjs2D&index=2&t=0s Movie (19:53) on Filters]..."

Childers at 21:19, 22 February 2012

2012-02-22T21:19:11Z

Rebull at 20:53, 22 February 2012

2012-02-22T20:53:58Z

Childers at 17:17, 21 February 2012

2012-02-21T17:17:03Z

Rebull at 18:29, 20 February 2012

2012-02-20T18:29:10Z

Rebull at 18:23, 20 February 2012

2012-02-20T18:23:49Z

Childers at 17:58, 20 February 2012

2012-02-20T17:58:46Z

← Older revision		Revision as of 17:18, 26 October 2020
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	=Other sources of interest=		=Other sources of interest=
−	[https://nightsky.jpl.nasa.gov/download-view.cfm?Doc_ID=675]	+	[https://nightsky.jpl.nasa.gov/download-view.cfm?Doc_ID=675 Clues to the Cosmos Activity] from NASA Night Sky Network

← Older revision		Revision as of 17:18, 26 October 2020
Line 14:		Line 14:

	=Other sources of interest=		=Other sources of interest=
		+	[https://nightsky.jpl.nasa.gov/download-view.cfm?Doc_ID=675]

← Older revision		Revision as of 19:01, 11 August 2020
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	*[https://www.youtube.com/watch?v=aYVEGkx0rUc&list=PLjCjDYabTFm9b9jQd4hcZPAnFWYsIjs2D&index=2&t=0s Movie (19:53) on Filters], part of the "Filters, Magnitudes, Colors, Oh My!" playlist -- Dr. Luisa Rebull, 2020		*[https://www.youtube.com/watch?v=aYVEGkx0rUc&list=PLjCjDYabTFm9b9jQd4hcZPAnFWYsIjs2D&index=2&t=0s Movie (19:53) on Filters], part of the "Filters, Magnitudes, Colors, Oh My!" playlist -- Dr. Luisa Rebull, 2020
		+
		+	=Other important CoolWiki pages=
		+	*[[FITS format]]
		+	*[[Astronomical imaging]]
		+	*[[Image artifacts]]

@@ Line 1: / Line 1: @@
-don't forget [[Units|this page]] which also may have some useful information for your discussion! :) --[[User:Rebull|Rebull]] 12:53, 22 February 2012 (PST)
+=Most coherent, developed, tested materials=
-== Convert Johnson Magnitude to Janskys ==
+*[https://www.youtube.com/watch?v=aYVEGkx0rUc&list=PLjCjDYabTFm9b9jQd4hcZPAnFWYsIjs2D&index=2&t=0s Movie (19:53) on Filters], part of the "Filters, Magnitudes, Colors, Oh My!" playlist -- Dr. Luisa Rebull, 2020
-<code><big>flux = 10^(-0.4*magnitude) * zero_point_flux ~ (0.3981)^magnitude * zero_point_flux</big></code>
+=Somewhat less coherent (or less standalone) materials=
-<math>\phi = 10^{(-0.4m)} \phi_0 \approx (0.3981)^m \phi_0 </math>
+=Other sources of interest=

@@ Line 10: / Line 10: @@
-<math>f = 10^{(-0.4m)} f_0 \approx (0.3981)^m f_0 </math>
+<math>\phi = 10^{(-0.4m)} \phi_0 \approx (0.3981)^m \phi_0 </math>
@@ Line 19: / Line 19: @@
 Because the AB magnitude system is defined by a fixed zero-point flux instead of a reference object, any AB magnitude can be converted to janskys with this formula:
-<code><big>flux = (0.3981)^magnitude * 3631 Jy</big></code>
+<code><big>flux = (0.3981)^magnitude * 3631  Jy</big></code>
 <math> \phi = (0.3981)^m \times 3631 \mathrm{Jy} </math>
@@ Line 118: / Line 118: @@
 Also one more finally, I used the term flux.  Actually, these conversions are from magnitude to FLUX DENSITY.  A flux density is an amount of energy per time per area per unit wavelength or frequency (hence the per Hz in the units of Jansky) whereas a flux is an amount of energy per unit time per area over all wavelengths.  The terminology is a detail that astronomers often use interchangeably - and often incorrectly.
 ----
 [[BOKO_Current_Research_Activities|Back to the BOKO home page]]

← Older revision		Revision as of 20:53, 22 February 2012
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	I found [http://www.astro.umd.edu/~ssm/ASTR620/mags.html this page] which was a helpful expansion on [[#David's_Original_E-Mail\|David's email]] of Feb. 11. Note however that the [http://www.astro.umd.edu/~ssm/ASTR620/mags.html#flux table for Photon Flux] has different central wavelengths for the AB filters than David did (the data for the Johnson filters all match). --[[User:Childers\|Childers]] 18:19, 19 February 2012 (PST)		I found [http://www.astro.umd.edu/~ssm/ASTR620/mags.html this page] which was a helpful expansion on [[#David's_Original_E-Mail\|David's email]] of Feb. 11. Note however that the [http://www.astro.umd.edu/~ssm/ASTR620/mags.html#flux table for Photon Flux] has different central wavelengths for the AB filters than David did (the data for the Johnson filters all match). --[[User:Childers\|Childers]] 18:19, 19 February 2012 (PST)
		+
		+	don't forget [[Units\|this page]] which also may have some useful information for your discussion! :) --[[User:Rebull\|Rebull]] 12:53, 22 February 2012 (PST)

	== Convert Johnson Magnitude to Janskys ==		== Convert Johnson Magnitude to Janskys ==

@@ Line 117: / Line 117: @@
 Also one more finally, I used the term flux.  Actually, these conversions are from magnitude to FLUX DENSITY.  A flux density is an amount of energy per time per area per unit wavelength or frequency (hence the per Hz in the units of Jansky) whereas a flux is an amount of energy per unit time per area over all wavelengths.  The terminology is a detail that astronomers often use interchangeably - and often incorrectly.
-'''''Disregard this, it is part of debugging LaTex on this page'''''
+'''''Disregard this, it is part of debugging LaTeX on this page'''''
 <math>B_{\lambda} = \left(\frac{2hc^2/\lambda^5}{\exp(hc/\lambda kT)-1)}\right)</math>

@@ Line 7: / Line 7: @@
 <code><big>flux = 10^(-0.4*magnitude) * zero_point_flux ~ (0.3981)^magnitude * zero_point_flux</big></code>
-<math> \phi = 10 ^{(-0.4m)} \phi_0 \approx (0.3981)^m \phi_0 </math>
+test
 Since the magnitude is a dimensionless quantity, the units for the flux will be identical to the units for the zero_point_flux.  In the table below, use the right-most column.

@@ Line 27: / Line 27: @@
 <code><big>magnitude = -2.5*log10(flux/zero_point_flux)</big></code>
-<math> m = -2.5 \log{\frac{\phi}{\phi_0}} </math>
+<math>m=-2.5\log{\frac{\phi}{\phi_0}}</math>
 where flux is the flux of the star and the zero_point_flux is the flux of a reference star DEFINED to have a magnitude = 0.0
@@ Line 114: / Line 114: @@
 Also one more finally, I used the term flux.  Actually, these conversions are from magnitude to FLUX DENSITY.  A flux density is an amount of energy per time per area per unit wavelength or frequency (hence the per Hz in the units of Jansky) whereas a flux is an amount of energy per unit time per area over all wavelengths.  The terminology is a detail that astronomers often use interchangeably - and often incorrectly.