Academy Saturday 28th November 1874
—ln the years 1869 and 1870 Professor Helmert, at the
Hamburg Observatory, determined the positions of some two hundred stars
belonging to the cluster in Sobieski’s Shield. This cluster, which was
discovered by Kirch in 1681, was carefully observed by Dr. Lamont at Munich
between 1836 and 1839, and the places of about 150 stars in its most condensed
part were then fixed with considerable accuracy for comparison with subsequent
observations. These Professor Helmert has now made after the lapse of more than
thirty years, so that if any change has occurred, and especially if there has
been any condensation going on, it ought to be clearly shown by comparing the
two sets of measures. The two series, however, agree so closely, that the
second set may be looked upon simply as a verification of the first—a result
which, though disappointing with respect to the object in view, must yet be
gratifying to both the observers concerned, :. Evidence of the accuracy of the
measures. Two charts present at a glance the results of the two determinations,
the only noticeable difference being that Professor Helmert has included many
more outlying stars in his area of operations.
www.theramblingastronomer.co.uk
No comments:
Post a Comment