Anthony J. Kroes Oct 7 12:05 PM
Possibly, but the newest version of Lynd’s Dark Nebula catalog (that I could find, anyway) is from 1997 through ftp://cdsarc.u-strasbg.fr/cats/VII/7A/ldn
and it still shows LDN 4 as being at RA 16 59.5 Dec -22 8 with a size of .004, just like the original catalog entry.
Does anyone know of a newer catalog version?
PS: Pierre, the ‘837’ on the designation is apparently a reference to a Barnard Object that goes along with the LDN (see http://heasarc.gsfc.nasa.gov/W3Browse/nebula-catalog/ldn.html) . However the Barnard Dark Nebula list I was able to find does not go that high, and Guide does not allow me to go to Barnard 837 through the ‘Goto>Nebula>Barnard Dark Nebula’ path, so I am not sure “which* Barnard listing it is referring to.
As I understand it the Lyynds catalogue was updated after its orginal publication and I suspect that Guide is using the latest version not the orginal. You can check in Simbad as to what goes where and probably download the current version from Vizier
catalogue evolution is a fact of life.
----- Original Message -----
Tue, 7 Oct 2014 10:23:22 -0500
RE: [guide-user] Lynd Dark Nebula used in GUIDE 9.0
I can verify that problem, Pierre. The original Lynd’s Catalog from 1962 shows LDN 2 at coordinates RA 18 4 Dec -31 30 which, once converted to epoch 2000 coordinates, gives RA 18h 07m 14.6s, Dec -31° 29m 35s, almost exactly what you got when plate-solving your image.
This is indeed where Guide shows LDN 4, which has the size of LDN 2 (1.24 sq. deg) listed for it as well. Guide shows nothing at all in the spot where LDN 4 should be according to the epoch-corrected coordinates from the Lynd catalog (RA 17h 2m 30.1s Dec -22° 12m 15.2s)
I searched through the Guide folders and subfolders doing various text searches and cannot find where the LDN data is either.
Few time ago, I ask information about the Lynd Dark Nebula catalog. Could you give more information about the LDN used by Guide 9.0
There is something strange in the catalog of Lynd Dark Nebulae and GUIDE.
Recently I took images of LDN 2, according to my Lynd Nebulae Catalog ( the original one published by Lynd). After made a registration of my picture to get the coordinated of the nebulae, I got 18h 07m 14,9s -31° 29' 31,6''. Putting those value in GUIDE, an I arrive dot LDB 4.
More confusing, Guide report the objet as LDN 4 (873). I try to get access to More information with the LND catalog use by GUIDE, but I seems that we don't have access to it.
Why there is a discrepancy between my catalog and the one use by GUIDE ?
What is the meaning of (873) reported by GUIDE for LDN 4 ?
Why are we unable to get acces to the catalog of LDN within GUIDE ?
What is the source of LDN catalogue used by GUIDE ?
Centre d'Observation Astronomique Des Monts Notre-Dame