Counting Stars on the Celestial Sphere?

Is there a source that has a count of stars in regions of the celestial sphere for stars
of magnitude 0, 1, 2, ..., 5? Maybe by an hour of RA and 15 degrees of Dec.
--
Wayne T. Watson (121.015 Deg. W, 39.262 Deg. N, 2,701 feet, Nevada City, CA)
-- GMT-8 hr std. time, RJ Rcvr 39° 8' 0" N, 121° 1' 0" W

"If I'm given six hours to cut down a tree, then I spend four hours
sharpening my axe." -- Abraham Lincoln

Web Page: home.earthlink.net/~mtnviews
sierra_mtnview -at- earthlink -dot- net
Imaginarium Museum: home.earthlink.net/~mtnviews/imaginarium.html

Wayne Watson wrote:
Is there a source that has a count of stars in regions of the
celestial sphere for stars of magnitude 0, 1, 2, ..., 5? Maybe by an
hour of RA and 15 degrees of Dec.

One thing to do is to get something like Cartes du Ciel, and set the
magnitude limits to the range you want to count. Then just do a visual
survey.

If you want a comprehensive survey of the entire sphere, you'll probably
have to download one of the star catalogues (Yale or Hipparcos) and do
your own data processing on it. I doubt that anyone has done this
count already and posted it on the Web. (But you never know--try
Googling it.)

Brian Tung
The Astronomy Corner at http://astro.isi.edu/
Unofficial C5+ Home Page at http://astro.isi.edu/c5plus/
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That would be interesting if you could do it. What drove me to ask this is that I'm doing
a TPoint alignment (polar) and fairly bright stars are helpful to do the mapping. As I
started searching around for candidates, many were obvious. However, there seem liked
large patches that were not well covered. I then started wondering how this looks
statistically. At this point it is a curosity, but interesting. I would guess someone has
done it before. Nothing specific on Google. Saw the ideas a class exercise.

Brian L. Rachford wrote:
On Sun, 23 Nov 2003 20:08:17 +0000 (UTC), Brian Tung penned:

Wayne Watson wrote:

Is there a source that has a count of stars in regions of the
celestial sphere for stars of magnitude 0, 1, 2, ..., 5? Maybe by an
hour of RA and 15 degrees of Dec.

One thing to do is to get something like Cartes du Ciel, and set the
magnitude limits to the range you want to count. Then just do a visual
survey.

If you want a comprehensive survey of the entire sphere, you'll probably
have to download one of the star catalogues (Yale or Hipparcos) and do
your own data processing on it. I doubt that anyone has done this
count already and posted it on the Web. (But you never know--try
Googling it.)


If there's nothing available via Googling, I have the Hipparcos
catalog in a form from which I can generate the star counts
pretty easily within the next day or two. (I find these sorts
of things interesting as well; I was recently playing around
with the same sort of thing with galaxies.)

Brian Rachford



--
Wayne T. Watson (121.015 Deg. W, 39.262 Deg. N, 2,701 feet, Nevada City, CA)
-- GMT-8 hr std. time, RJ Rcvr 39° 8' 0" N, 121° 1' 0" W

"If I'm given six hours to cut down a tree, then I spend four hours
sharpening my axe." -- Abraham Lincoln

Web Page: home.earthlink.net/~mtnviews
sierra_mtnview -at- earthlink -dot- net
Imaginarium Museum: home.earthlink.net/~mtnviews/imaginarium.html

On Sun, 23 Nov 2003 19:29:10 GMT, W. Watson penned:
Is there a source that has a count of stars in regions of the celestial
sphere for stars of magnitude 0, 1, 2, ..., 5? Maybe by an hour of RA
and 15 degrees of Dec.

Okay, here it is. I was able for format it short enough to post
here; it's shorter than many of my observing reports, anyway.

The following lists give the number of stars in each magnitude
bin in RA and Dec ranges, based on the Hipparcos catalog. I
have used the ground-based visual magnitudes listed in the
catalog as opposed to the Tycho "psuedo-visual" magnitudes.
Thus, this should be quite similar to the results one would get
with the Yale Bright Star Catalog (which I didn't happen to have
in a good format to crank this out). The RA is given across the
top of each list; for example, "23" means 23.0 hours to
23.99999... hours. For declination, "+75+90" means +75.0
degrees to +89.99999... degrees. Keep in mind that the mag bins
are not cumulative; that is, they only correspond to the listed
range and do not include the stars in brighter bins. I did some
limited "reality checks" on the results; i.e., I checked that it
got the bright stars where they should be. I did not do any
checks on the fainter bins, but they should be good. There are
no guarantees that the totals are complete, especially for the
fainter stars (the Bright Star Catalog might be slightly more
complete than Hipparcos). The plane of the Milky Way shows up
very nicely in the 5th magnitude bin.

Brian Rachford



V 0.50
23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
+75+90 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
+60+75 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
+45+60 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0
+30+45 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
+15+30 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0
+ 0+15 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 1 0 0 0 0 0
- 0-15 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0
-15-30 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0
-30-45 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
-45-60 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 1 0 0 0 1 0
-60-75 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
-75-90 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

V = 0.50-1.49
23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
+75+90 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
+60+75 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
+45+60 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
+30+45 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
+15+30 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 1 0 0 0 0
+ 0+15 0 0 0 0 1 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0
- 0-15 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0
-15-30 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
-30-45 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
-45-60 0 0 0 0 0 0 0 0 0 2 0 1 0 0 0 0 0 0 0 0 0 0 0 0
-60-75 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0
-75-90 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

V = 1.50-2.49
23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
+75+90 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0
+60+75 0 0 1 0 0 0 0 0 0 1 0 0 1 0 0 0 0 0 0 0 0 0 0 1
+45+60 0 0 0 0 0 0 1 0 0 0 2 1 2 0 0 0 0 0 0 0 1 0 0 2
+30+45 0 0 0 2 0 0 0 0 0 0 0 0 0 0 0 0 1 0 1 0 1 1 1 0
+15+30 2 0 0 0 0 0 0 0 1 1 0 0 0 1 0 0 0 1 1 0 0 1 0 1
+ 0+15 0 0 1 0 0 0 1 0 0 0 0 0 1 0 0 0 0 0 2 0 0 0 0 0
- 0-15 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 3 0 0 0 0 0
-15-30 0 0 0 0 0 1 0 1 0 0 0 0 0 0 0 0 2 2 0 0 0 0 0 1
-30-45 0 0 0 0 0 1 3 1 0 2 0 0 0 0 1 1 0 0 0 0 0 0 0 1
-45-60 0 2 0 1 0 0 0 0 0 1 1 2 0 0 2 3 0 0 0 0 0 0 0 0
-60-75 0 0 0 0 0 0 0 1 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0
-75-90 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

V = 2.50-3.49
23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
+75+90 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
+60+75 0 0 1 1 1 0 1 1 1 0 0 0 0 0 0 1 0 0 0 0 0 0 2 0
+45+60 0 1 0 0 1 0 1 0 1 0 0 1 0 0 1 1 0 0 0 0 2 0 0 1
+30+45 0 1 1 0 0 1 1 2 2 1 0 1 2 2 1 0 0 0 3 1 3 1 0 1
+15+30 0 0 0 0 1 0 2 1 0 0 1 0 2 2 1 0 0 3 1 1 1 0 2 1
+ 0+15 0 2 0 1 3 0 2 1 1 0 2 1 0 0 0 2 1 1 1 2 1 1 0 0
- 0-15 0 1 1 1 1 1 1 3 1 0 0 1 0 0 0 0 0 0 3 0 1 0 2 0
-15-30 0 0 1 0 3 4 1 3 2 2 1 4 0 1 0 1 3 1 4 0 0 0 0 0
-30-45 0 0 1 0 0 2 4 2 3 2 3 0 0 0 0 0 2 1 2 0 0 1 1 0
-45-60 0 2 0 1 0 0 3 1 1 0 1 2 0 1 2 0 1 1 0 1 0 0 1 0
-60-75 0 0 0 1 0 0 0 0 2 1 0 2 1 4 1 0 0 1 0 1 1 0 1 0
-75-90 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1

V = 3.50-4.49
23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
+75+90 1 0 0 1 0 0 1 1 1 1 0 0 0 0 1 0 0 0 0 0 0 0 1 0
+60+75 0 2 1 1 2 2 0 0 0 1 0 1 1 0 1 0 0 0 1 1 1 3 0 1
+45+60 1 5 3 3 3 0 2 2 0 2 1 0 1 0 4 0 0 2 2 4 4 3 4 2
+30+45 3 2 4 4 3 5 4 2 2 1 0 1 1 3 2 1 2 1 2 1 4 2 1 2
+15+30 1 3 4 3 5 7 2 1 6 2 3 1 1 1 3 2 7 3 2 10 7 1 2 3
+ 0+15 6 4 2 2 3 4 2 2 4 3 0 2 5 3 2 7 2 7 4 9 4 5 3 1
- 0-15 4 5 0 5 2 2 3 1 2 4 1 0 2 1 2 3 2 3 9 6 4 2 2 2
-15-30 4 1 5 3 2 2 4 7 5 1 0 2 2 2 0 2 8 5 2 3 5 2 0 2
-30-45 4 6 1 0 8 0 1 5 4 8 6 1 4 2 2 7 4 4 3 4 3 2 0 2
-45-60 2 0 2 1 0 2 1 4 5 4 1 7 2 5 5 5 4 2 1 2 0 2 4 1
-60-75 1 0 1 2 0 5 1 1 1 0 1 5 3 1 4 2 3 0 2 1 1 2 1 2
-75-90 0 1 1 0 0 0 0 2 0 2 0 1 0 2 0 2 0 0 0 0 0 0 0 0

V = 4.50-5.49
23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
+75+90 0 4 0 2 1 1 1 2 1 1 0 3 0 2 0 1 3 1 2 3 2 2 0 0
+60+75 5 8 7 4 2 4 5 5 3 2 1 5 3 3 7 4 0 5 2 3 9 1 6 4
+45+60 13 11 5 9 10 7 5 7 4 4 6 4 2 4 8 2 8 10 6 8 14 7 6 10
+30+45 4 8 7 12 15 12 7 9 12 4 7 4 5 8 8 4 7 7 14 7 7 14 7 8
+15+30 7 3 6 18 11 14 5 8 9 6 4 16 3 3 4 9 15 9 18 17 8 11 9 9
+ 0+15 12 9 4 9 13 11 6 8 7 6 6 5 12 7 10 3 11 8 17 23 4 8 4 1
- 0-15 10 6 8 7 13 13 6 9 8 9 7 5 5 6 10 9 13 24 21 11 8 8 8 10
-15-30 8 7 11 4 12 15 7 12 12 9 9 5 8 5 11 7 20 11 6 4 5 8 4 10
-30-45 4 9 8 9 6 22 9 13 17 5 6 8 11 3 10 16 27 8 8 4 4 4 6 3
-45-60 3 4 1 7 6 5 8 8 6 8 12 14 9 15 10 23 12 7 10 2 1 4 4 3
-60-75 1 3 2 4 2 4 2 4 4 3 7 5 14 11 7 9 0 7 6 4 3 4 2 5
-75-90 1 3 3 0 0 1 0 2 0 3 0 2 1 1 3 2 0 1 2 0 0 1 0 2

Brian L. Rachford wrote:

Okay, here it is. I was able for format it short enough to post
here; it's shorter than many of my observing reports, anyway.
...

In the table for V = 4.50-5.49, the Milky Way is clearly visible.
Not surprising, but I find it nice anyway...

Regards,

- Alex