3 research outputs found
Early star catalogues of the southern sky: De Houtman, Kepler (Second and Third Classes), and Halley
De Houtman in 1603, Kepler in 1627 and Halley in 1679 published the earliest
modern catalogues of the southern sky. We provide machine-readable versions of
these catalogues, make some comparisons between them, and briefly discuss their
accuracy on the basis of comparison with data from the modern Hipparcos
Catalogue. We also compare our results for De Houtman with those by Knobel
(1917) finding good overall agreement. About half of the about 200 new stars
(with respect to Ptolemaios) added by De Houtman are in twelve new
constellations, half in old constellations like Centaurus, Lupus and Argo. The
right ascensions and declinations given by De Houtman have error distributions
with widths of about 40 arcmin, the longitudes and latitudes given by Kepler
have error distributions with widths of about 45 arcmin. Halley improves on
this by more than an order of magnitude to widths of about 3 arcmin, and all
entries in his catalogue can be identified. The measurement errors of Halley
are due to a systematic deviation of his sextant (increasing with angle to 2
arcmin at 60 degrees) and random errors of 0.7 arcmin. The position errors in
the catalogue of Halley are dominated by the position errors in the reference
stars, which he took from Brahe.Comment: 26 pages, 58 figures. Tables will become available at CDS once the
article appears in Astronomy and Astrophysic
