Talk:Apparent magnitude

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Formulas! We should include formulas here and in absolute magnitude.--AN

The 1st paragraph for this page gets confusing rather quickly. Would it be possible for someone with knowledge of the subject to clarify the definition before jumping into numerical examples?

The current definition seems to be fine but the first paragraph was needlessly complex to be sure. I took out the, imo, unneeded part and left it at that, brief. I also took the liberty of pulling the sections regarding the history of the system up to just after the introductory sentences since that seemed more logical to me. I anyone has a problem with that please discuss it here. I'm sure the article could use more tweaking and maybe someone can do that or I'll come back to it later. --Kalsermar 23:14, 6 October 2005 (UTC)

Contents

[edit] Magnitude (astronomy)

When amateurs refer to magnitude in astronomy, they probably don't know the difference between apparent magnitude and absolute magnitude. This also creates a problem for the disambigation link repair: I, for example, have no idea whether to pipe magnitude link from (exampple) All Sky Automated Survey article to absolute or apparent. Could sb create the article in the heading explaining the basic magnitude idea in astronomy and comparing the specific types, so the current two articles would become subarticles? Note that currently it is a redirect to magnitude disambig - far from a pefect solution.--Piotr Konieczny aka Prokonsul Piotrus Talk 17:47, 9 January 2006 (UTC)

I changed Magnitude (astronomy) to a disambiguation page with short descriptions for the two types of magnitudes. Hopefully they make disambiguating little easier. I don't think that absolute magnitude is mentioned in many articles compared to apparent magnitude. For example, when the article says "limiting magnitude is n", "stars brighter than n magnitude" or "nth magnitude star", magnitude always refers to the apparent magnitude.--Jyril 23:21, 9 January 2006 (UTC)

[edit] So what is the standard?

Maybe I missed it, but I cannot find the modern reference point from which all other magnitudes are determined. I see that Vega used to be defined as zero, but not what the new standard is.


- me neither. Article doesn't explain either the Zero or any reason for the step size. I assume there is one?

[edit] Apparent magnitude of nebulous objects

I miss information on how the apparent magnitude of dim objects (galaxies, nebulae) is calculated, and how that is related to their visibility. Is the Triangulum Galaxy equally visible on the night sky as a star with the same magnitude? Apus 09:00, 25 October 2006 (UTC)

[edit] Bad editions

I see, that some information were lost during editions (for example interwiki). Someone should check the history carefully. 83.14.10.10 15:31, 31 October 2006 (UTC)

[edit] B or V for apparent magnitude.

In Talk:Andromeda_Galaxy#Apparent_magnitude the suggestion has been made "In general, it is much easier to find B magnitudes than it is to find V magnitudes, so B magnitudes are generally used in the infoboxes. However, the infoboxes are set up with "(V)" hardwired into them. It might be better just to set up the infoboxes so that the wave band may be specified in the inserted text rather than in the template".

However, this article says "The V band was chosen for spectral purposes and gives magnitudes closely corresponding to those seen by the light-adapted human eye, and when an apparent magnitude is given without any further qualification, it is usually the V magnitude that is meant, more or less the same as visual magnitude". Is there a good resolution for this? I have also posted on Template:Galaxy. Thincat 10:19, 6 June 2007 (UTC)

[edit] Scale of Apparent Magnitude

Nearly one year ago, on October 29, 2006, the table titled Scale of Apparent Magnitude was deleted because the URL of the source could not be found. As of September 15, 2007, the table has been reinserted into the article, this time with a URL to Jim Kaler's THE 151 BRIGHTEST STARS. The fourth paragraph of Kaler's article provides at least some of the information and data shown in the table. I will personally search for additional sources (URLs) dealing with this exact subject and insert them onto the table. However, I perfectly welcome the contributions of other Wikipedia editers to the Scale of Apparent Magnitude data table, because I feel that this table would prove very beneficial to anyone curious about the various orders of magnitude and how they are distinguished from each other. --Richontaban 16:19, 15 September 2007 (UTC)

[edit] Consistency?

In some calculations on this page the value '2.5' is used. Other calculations use '2.512'. Shouldn't they at least be consistent? Dfmclean 18:17, 11 October 2007 (UTC)

The correct value is the (5th root of 100) = 2.511886432. But yes, humans like to round off for simplicity. 2.5^5 is only 97.65625. -- Kheider 20:57, 11 October 2007 (UTC)

-Actually, In Pogson's equation, 2.5 is 2.50000, an exact number from 5/2, not a round off of the number 2.512. The value 2.512 is found for the ratio of brightness between adjacent integer magnitudes. (i.e. It is the fifth root of 100). The 2.5 from Pogson's equation is thus completely different from 2.511886432...

[edit] Total integrated magnitude of the night sky

Hypothetically speaking, if the Sun was to suddenly wink out at this instant in time, the total isotropic radiation flux falling on the Earth's surface from the surrounding cosmic night sky would amount to -6.5 magnitudes. This quantity was first determined by Abdul Ahad (b. 1968-) and is generally known as Ahad's Constant [1]. 90.193.170.221 (talk) 14:35, 8 March 2008 (UTC)