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Barnard's Dark Nebulae Sky Database (SDB)349 objects
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 Edit | Find Barnard NUMBER to
search 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 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 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 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 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! 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 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 Versus
Original size and position
My drawing for the HorseHead
Icing on the cake...
Anglo Australian Observatory Copyright notice 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. 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 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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