Known to Aratos 260 B.C.
[Mem. Acad. for 1771, p. 451-452 (first Messier catalog)]
At simple view [with the naked eye], one sees in Cancer a considerable
nebulosity: this is nothing but a cluster of many stars which one
distinguishes very well with the help of telescopes, & these stars are
mixed up at simple view [to the unaided eye] because of their great
proximity. The position in right ascension of one of the stars, which
Flamsteed has designated with the letter c, reduced to March 4, 1769,
should be 126d 50' 30", for its right ascension, & 20d 31' 38" for its
northern declination. This position is deduced from that which Flamsteed has
given in his catalog.
[p. 458]
1769.Mar. 4. RA: 126.50.30, Dec: 20.31.38.B.
Cluster of stars known by the name of the nebula of Cancer: the position
reported is that of the star c.
[Messier reports to have measured the stars of the Praesepe cluster in 1785, 1790, and 1796.]
No. m RA Dec 38 o 8 127:38 08:30.6 +20:32 39 6 127:39 08:30.6 +20:46 40 6 127:46 08:31.1 +20:47 41 i 7 127:57 08:31.8 +20:18 42 c 7 128:02 08:32.1 +20:30The small cluster of stars Praesepe in Cancer is represented in the 16th plate in the upper part, to the right, by 12 of the principle stars after Flamsteed & T. Mayer. But on the 30th plate, Fig. 3, it is represented consisting of 40 stars accordint to the observations of de la Hire & Maraldi.
[Plate XXX, p. 38]
Fig. 3.
The wellknown star cluster in Cancer, the Praesepe or Manger
with 40 stars visible throgh telescopes projected after Maraldi and
de la Hire.
Last Modification: January 18, 2007