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4/13/2011

Herschel 400 II List

I know I've had some visitors looking for the H-400 II list so I thought I would put it up. Lists are interesting to me in some ways. They provide a way to explore items/objects to some, a way to earn the Astronomical Award for others, while for others (me) it just gives me s systematic way to go about observing. However, I am finding instead that I like to come up with my own projects or to take a constellation and just work my way through all the objects there.

My own project that I want am hoping to get started is to take some of the more well known objects and to sketch them in a light pollution zone say orange, and then to re-sketch/observe the same item at a dark sky site. Why? Because I want those who may not have the chance to get to a true dark site to be able to compare via my crude sketches what the differences are between seeing an object at a light polluted zone and in a dark zone. I want to shoot for 4 to 6 items per season. Winter was a failure and spring isn't looking too much better.

So here are the links to the Herschel 400 list. I have been working my way through this as I am in a constellation and for now, that is good enough. The links are to my Google Documents page. Herschel 400 II by sort and Herschel 400 II. The first link was set up to be able to sort it, but Google Documents may not have transferred that feature. Hope that helps someone.

2 comments:

  1. Dean Norris5/03/2011

    Jay,

    I've downloaded the Herschell 2 list you posted here and want to thank you for the great list. I've already found a few of them from my backyard in a red zone. I do a few questions about the list concerning the magnitudes of the objects.
    Here is what I am assuming about the magnitudes:
    V Mag means visual magnitude.
    B Mag means ??
    Surf BR means surface brightness of an object which is affected by the size and visual magnitude.
    Are the NGC comments abbreviations the same as the ones used in Burnhams Handbooks?

    Sorry about all the questions, I hope that's ok.

    Thanks again thank you for the great list.

    Dean

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  2. Hi Dean,

    V magnitude is visual magnitude. B Magnitude is called Blue Magnitude or photographic magnitude. To quote and corrections are welcome or clafification: "

    Before the advent of photometers which accurately measure the brightness of astronomical objects, the apparent magnitude of an object was obtained by taking a picture of it with a camera. These images, made on photoemulsive film, were more sensitive to the blue end of the visual spectrum than the human eye or modern photometers. As a result, bluer stars have a lower (i.e. brighter) photographic magnitude than their modern visual magnitude, because they appear brighter on the photograph than they do to modern photometers. Conversely, redder stars have a higher (i.e. fainter) photographic magnitude than visual magnitude, because they appear dimmer. For example, the red supergiant star KW Sagittarii has a photographic magnitude of 11.0 to 13.2 but a visual magnitude of about 8.5 to 11. It is also common for star charts to list a blue magnitude (B) such as with S Doradus and WZ Sagittae.

    The symbol for apparent photographic magnitude is mpg and the symbol for absolute photographic magnitude is Mpg."

    I assume that Burnham used the JLE Dreyer's description as found at these links:

    http://x.astrogeek.org/articles/article.php?article_id=2

    http://obs.nineplanets.org/ngc.html

    http://www.nexstarsite.com/DreyerDescriptions.htm

    Most people using Dreyer's descriptions use the system of short hand that he devised.

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