Constellation Circinus (Compass)

Circinus
Circinus: IAU Constellation Map [150]

Properties

The constellation Circinus, which is very small at 93 square degrees, is located east of the star Rigil Centaurus. It is roughly similar to the Triangulum constellation in the northern sky, because with its three brightest stars alpha, beta and gamma (3rd to 4th size) it forms a similarly narrow, pointed triangle that is supposed to represent a slightly spread circle. At least it is in the Milky Way and therefore still contains a few star clusters. The constellation culminates around midnight on May 1st. [9, 15]

Data for constellation Circinus [150]
IAU NameCircinus
IAU GenitiveCircini
IAU Abbr.Cir
English NameCompass
Season (47° N)Not visible
Right Ascension13h 38m 43s … 15h 30m 22s
Declination-70° 37' 28" … -55° 26' 11"
Area93 deg2
Neighbours (N↻)Lup, Cen, Mus, Aps, TrA, Nor

History

This inconspicuous constellation was introduced in 1752 by the French astronomer Lacaille. It represents a circle of drawings and, together with Norma (angle measure), is intended to remind of the navigational aids used by seafarers. [7]

Abbé Nicolas Louis de Lacaille was born in Rumigny, France, in 1713. Until 1739 he taught mathematics at the Mazarin College in Paris. In 1750 he traveled to the Cape of Good Hope in South Africa and introduced 14 new constellations, mostly taking apart old and larger ones. He also made important measurements on the moon, Venus and Mars and cataloged around 10,000 stars. On his return to Paris he revised his data - a process in which he was surprised by his death in 1762. His Coelum Australe Stelliferum was published the following year. [133]

Catalogs

Yale Bright Star Catalogue, 5th Revised Ed. (Hoffleit+, 1991) [154]
HR B F RA [hms] Dec [dms] vMag spType dMag Sep ["]
5463α14 42 30.4-64 58 313.19 ApSrEuCr: 5.415.6
5539ζ14 54 42.4-65 59 296.09 B3Vn
5551θ14 56 44.0-62 46 515.11 B4Vnpe v0.00.1
5593η15 04 48.2-64 01 545.17 G8III
5664δ15 16 56.7-60 57 275.09 O8.5V 8.350.
5666ε15 17 38.9-63 36 384.86 K2.5III
5670β15 17 30.8-58 48 044.07 A3V
5704γ15 23 22.7-59 19 154.51 B5IV+F8 0.30.9

Revised+Historic NGC/IC, Version 22/9, © Dr. Wolfgang Steinicke [277]
Planetary Nebulae
NameRADecTypebMagvMagDimDreyer DescriptionIdentification, Remarks
NGC 531513 53 57.1-66 30 48PN13.09.80.23planetary, stellar = 10.5 magPK 309-4.2, ESO 97-PN9, CS=11.3
Open Clusters
NameRADecTypebMagvMagDimDreyer DescriptionIdentification, Remarks
NGC 528813 48 45.6-64 41 11II2p11.83Cl, S, C, iR, st 14OCL 910, ESO 97-SC7
NGC 535913 59 48.0-70 24 00OCL8Cl, vL, lRi, lC, st 11ESO 66-SC4
NGC 571514 43 39.0-57 34 13II2m9.87Cl, L, p Ri, CM, st 11…13OCL 929, ESO 176-SC2
NGC 582315 05 30.5-55 36 13III2m7.912Cl, cL, Ri, lCM, st 13…14OCL 936, ESO 176-SC11

References

7«Der grosse Kosmos-Himmelsführer» von Ian Ridpath und Wil Tirion; Kosmos Verlag; ISBN 3-440-05787-9
9«Drehbare Sternkarte SIRIUS» von H. Suter-Haug; Hallwag-Verlag, Bern
15«Hartung's Astronomical Objects for Southern Telescopes» by David Malin and David J. Frew; Melbourne University Press 1995; ISBN 0-522-84553-3
133Deepsky Atlas of the Hawaiian Astronomical Society; hawastsoc.org/deepsky
150IAU: The Constellations, 11. Oktober 2020; iau.org/public/themes/constellations
154Yale Bright Star Catalog, 15. Oktober 2020; tdc-www.harvard.edu/catalogs/bsc5.html
277«Historische Deep-Sky Kataloge» von Dr. Wolfgang Steinicke; klima-luft.de/steinicke (2021-02-17)