.. under construction and preliminary ..
The "missing" Lacaille objects
Nine of the 42 entries in
Lacaille's Catalogue of Nebulae in the Southern Skies are not commonly
recognized as Deepsky Objects. Glen Cozens (gc) has investigated Lacaille's
positions/entries for these objects, which in turn caused the present author
to have a closer look on these identifications and the result.
This work is still in flow, so the preliminary material given here should be
taken with the appropriate care.
Independently, Ronald Stoyan (rs) of Germany has taken a new effort to
identify the missing Lacaille objects.
Please email me any comments,
corrections, errata and contributions.
Moreover, Glen supposes that the identification of Lacaille I.11 with
may be erroneous because of a deviating position, but it may be NGC 6634
instead (an asterism of three stars of mag 8.3, 7.8, 8.7).
Ronald confirms this notion, but from Lacaille's description (and in agreement
with the present author), concludes that Messier's identification with M69 has
- Lac I.13 (NGC 6777, GC 4484; double star)
- Two stars mag 8.0 and 8.3 [gc]
- strange that Lacaille found it resembling the preceding, Lac. I.12 =
Formerly, induced by this description, Owen Gingerich (1960) had proposed this
object might be identified with globular cluster NGC 6752, but this globular is
over 12 deg away from Lacaille's position [rs].
- Lac II.1 (asterism)
- Twelve stars of mag 7.6 to 9.5 [gc].
- Lac II.2 (open cluster?)
- Eight stars of mag 5.9 to 8.9 [gc].
May be open cluster Collinder 140, which is
2 deg N [rs].
- Lac II.6 (open cluster?)
- Open Cluster Trumpler 10 [gc, confirmed by rs].
This cluster is situated about 12' W and 11' S of Lacaille's position.
It is of 15' apparent diameter, total visual mag 4.6, with about 40 stars
up to mag 6.42, so clearly within the reach of Lacaille's equipment (even
visible to the naked eye under good observing conditions).
- Lac II.11 (asterism)
- Line of 8 stars mag 6.6 to 8.5 [gc].
- Lac III.1 (star)
- Star mag 7.2 [gc],
= HD 32806 = SAO 217150 of mag 7.1 [rs].
- Lac III.3 (open cluster?)
- Open Cluster van den Bergh-Hagen (vdB-Ha) 47.
This cluster is situated very close to Lacailles position (2' W, 1' S)
which is well within the cluster's diameter of 13' [hf, confirmed by gc and rs].
- Lac III.9 (asterism)
- Three stars of mag 8.1, 7.6, 7.9 [gc].
- Lac III.14 (asterism)
- Three stars of mag 8.4, 8.2, 9.1 [gc].
This NGC entry comes from John Herschel's GC, where it was entered in an
appendix as GC 5076, explicitely referring to (and apparently copied unverified
from) Lacaille I.11, and described as "Nebula without stars."
Ronald further mentions that former attempts by Owen Gingerich (1960) and
Kenneth Glyn Jones (1975) of the identification of Lac II.8 (with
NGC 3293) failed due to unknown strange reasons.
Vehrenberg has it, though.
Also, Ronald finds from its description and position that Lacaille III.5
is probably open cluster Collinder 228, situated
in the southern part of the Eta Carinae Nebula
NGC 3372, not a duplication of Lacaille
III.6 as is proposed by Vehrenberg (following Gingerich).
- Cozens, Glen, private communications 1998-2000.
- Gingerich, Owen, 1960.
Abbe Lacaille's List of Clusters and Nebulae. Sky & Telescope 2/1960.
- Glyn Jones, Kenneth, 1975.
The Search for the Nebulae.
- Stoyan, Ronald, 2001. Der Katalog von [The catalogue of]
Abbé Nicolas-Louis de Lacaille (1713-1762).
interstellarum No. 18 (July 2001), p. 46-48. In German.
- Vehrenberg, Hans, Atlas of Deep Sky Splendors.
Vehrenberg+Sky Publishing. 1st ed 1965, 3rd ed. 1978.
Chapter on "La Caille and his catalogue of southern objects."
Last Modification: 26 Dec 1999, 22:45 MET