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Because the text file has been compiled using
a field to "SEARCH" for specifically columns 20-24 as explained above, the data can be
searched in TheSky using
the find dialog (Edit | Find). You must precede the Find entry with
Barnard then enter the NUMBER you wan to search for.
Example: Find Barnard 33
returns the following:
Object name: Barnard: 33
Magnitude: 0.0
Equatorial: RA: 05h 40m 47s Dec: -02°27'17"(current)
Equatorial 2000: RA: 05h 41m 00s Dec: -02°27'00"
Horizon: Azim: 201°46'30" Alt: +45°35'38"
Visibility: Rise 17:06, Set 04:58
Transit time: 23:00
Source catalog: Sky Database: Barnard
DB field 1: Barnard Number: 33
DB field 2: Other ID: IC434
DB field 3: Common Name: HorseHead Nebula
DB field 4: Size (arc minutes): 5.5
Hour angle: 00h 59m 59s
Air mass: 1.40
Sidereal time: 06:41
Click distance: 2.0000
Celestial type: 16
Index: 32
Julian date: 2449718.7917
Catalog: 9
Edit | Find Barnard NUMBER to
search
Each entry from the SEARCH field listed
If you wish to have each object
centered for you and the Object Information displayed as you scroll down the
list just place a check in the Frame Object and Object Information boxes as
shown above.
To label the fields use View | Display
Explorer and EXPAND the "LDN" entry under Sky Databases (SDB's) as
shown below. There you can place a check mark next to the
fields you wish to have labeled on the screen.
Pick fields you want labeled
View | Display Explorer
Next make sure the "EXTENDED
LABELS" are set to "visible" AND secondly make sure the Object Type Dark
Nebula is also enabled. View | Labels | Extended Labels for labels and
View | Display Explorer | Dark Nebula is set to visible.
Keep in mind that enabling several
fields at once clutters the screen.
View | Labels | Extended Labels
Make sure they are checked!
Also enable Dark Nebula
Make sure Dark Nebulae are visible
Lastly. Use the Display Properties for Dark
Nebulae to set the Font type, size, color, nebulae fill color, etc.
See below.
View | Display Explorer | Display Properties
Choose what suits you!
Recompiling the data is quite
simple BECAUSE the header does all the work for you! If you wish to
change the Search field, or the order of the fields shown in the Object
Identification dialog feel free to do so.
Make any changes you want then just use Data | Import and Browse the text file
by name on your local drive and press the "COMPILE" button highlighted
below.
Data | Import
Then press Compile
The following is near the star
Antares in the constellation Scorpious. Note the approximate size of
the Dark Nebulae and their labels are shown!
Wow, cool!
43 degree field 17h 24m 25.1s -35d 1m 52s
And now consider this! Following is a
chart showing the entries from the Lynds' Dark Nebula and also the data from the
catalog of Barnard's Dark Nebula for comparison. It should be noted that
very few, if any, datasets out there today are 100% perfect in all regards!
Lynds and Barnard's Dark
Nebula
click on image for Hires full size
Note discrepancies!
The green labels and turquoise
circles are the Lynds data, yellow labels and blue circles are the Barnard
entries, and the label Snake Nebula is my own entry. These kinds of errors
(positional, magnitude, and/or size errors) are quite common in many of the
datasets that exist.
Catalog Capriciousness
<----Click here for a complete synopsis on-line reprint of a very
informative article by Stuart Goldman of
Sky and Telescope magazine.
I chose to add 3 fields to the data.
A magnitude field, common name, and other ID. This allowed me
to assign the common name "Horsehead nebula" and "Snake Nebula" to
the appropriate objects. More will follow.
I also took the liberty to adjust the
entry for the HorseHead nebula for position and size to something I
felt was better. Artistic license if you will. The
original entry is still included merely commented out with a semi
colon. My position and
size
improvised if you will
Nice fit!
Versus
Original size and position
You be the judge!
My drawing for the HorseHead
Again artistic license?
Icing on the cake!
Lastly
Anglo
Australian Observatory Photo!
Photographs in the
Anglo-Australian folder of TheSky’s media are copyright ©
Anglo-Australian Observatory (AAT images)
and/or © ROE/AATB (UK Schmidt Telescope images) and are reproduced with
permission. Photographs from the Anglo Australian Observatory telescopes are by
David Malin.
Background information
VII/220A Barnard's Catalogue of 349 Dark Objects in the Sky (Barnard, 1927)
================================================================================
Barnard's Catalogue of 349 Dark Objects in the Sky
Barnard E.E.
<A Photographic Atlas of Selected Regions of the Milky Way,
by Barnard E. E., ed. Frost E.B. and Calvert M.R.,
Carnegie Institution of Washington (1927)>
=1927cdos.book.....B
=1927Barn..C......0B
================================================================================
ADC_Keywords: Nebulae, dark ; Nonstellar objects
Keywords: Dark objects ; Barnard objects
Description:
This catalogue was created based on the
original published catalogue
by Barnard E.E., 1927, Carnegie Institution of Washington,
"A photographic Atlas of selected regions of the Milky Way".
The catalogue contains positions of 349 Barnard Objects.
The objects with numbers from 1 to 175 are classified in the first
Barnard catalogue (1919ApJ....49....1B); three of the objects in that
list have been omitted here (Nos 52, 131a, and 172) because these
objects had been listed twice.
The objects from Barnard's second list are numbered from 201 to 370 --
there are therefore no objects having the numbers from 176 to 200.
Their positions were determined by Miss Calvert.
The epoch for all positions in the original published catalogue was
1875.0. Positions for both 1875.0 and 2000.0, the diameters and the
notes are included in this machine-readable catalogue.
The field information used for the data
is detailed here,
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
2- 5 A4 --- Barn *[ 0-9a]! Barnard number
6- 7 I2 h RAh Right Ascension 1875 (hours)
9- 10 I2 min RAm Right Ascension 1875 (minutes)
12- 13 I2 s RAs *? Right Ascension 1875 (seconds)
15 A1 --- DE- Declination 1875 (sign)
16- 17 I2 deg DEd Declination 1875 (degrees)
19- 20 I2 arcmin DEm Declination 1875 (minutes)
23- 24 I2 h RA2000h Right Ascension 2000 (hours)
26- 27 I2 min RA2000m Right Ascension 2000 (minutes)
29- 30 I2 s RA2000s ? Right Ascension 2000 (seconds)
33 A1 --- DE2000- Declination 2000 (sign)
34- 35 I2 deg DE2000d Declination 2000 (degrees)
37- 38 I2 arcmin DE2000m Declination 2000 (minutes)
40- 44 F5.1 arcmin Diam ? Diameter of the nebula
And the above fields translate into the
following "HEADER" text for
TheSky. Please refer to
TheSky's documentation for
details on TheSky
Database Files (SDB's).
;copyright Software Bisque 2005 http://www.bisque.com
>SEARCH 20,24
>ALIAS 50,59
>RAHOURS 5,6
>RAMINUTES 8,9
>RASECONDS 11,12
>DECSIGN 14,14
>DECDEGREES 15,16
>DECMINUTES 18,19
>MAGNITUDE 88,93
>MAJOR AXIS 43,47
>MINOR AXIS 43,47
>PARSE "Barnard Number" 20,24
>PARSE "Other ID" 50,59
>PARSE "Common Name" 60,86
>PARSE "Size (arc minutes)" 43,47
>IDENTIFIER Barnard
;The CDS Service for astronomical Catalogues
;http://cdsweb.u-strasbg.fr/viz-bin/VizieR-3
>OBJECT TYPE 16
;16 = Dark Nebulae
>LOADMEMORY
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