Several observers, including Huggins, Salter, and others, had
previously drawn faint stars in the interior of the trapezium; but
these could not be seen by Hall and Burnham in the large refractors at
Washington and Chicago, and were thus proved to have no real existence.
The new stars observed in the 36-inch telescope are only just within
the limits of its capacity, and therefore cannot be identical with
stars alleged to have been previously seen in small instruments.
The fifth and sixth stars in the trapezium have been supposed to be
variable, and not without reason; possibly the others are equally
liable to change, but this is only conjecture. Sir J. Herschel says
that to perceive the fifth and sixth stars “is one of the severest
tests that can be applied to a telescope” (‘Outlines,’ 11th edit. p.
610); yet Burnham saw them both readily in a 6-inch a few minutes
before sunrise on Mount Hamilton in September 1879.
β and ε Lyræ also form multiple groups, which will well repay
observation either with large or small telescopes.
_Further Observations._—Anyone who attempts to indicate with tolerable
fulness the methods and requirements of observation in the stellar
department of astronomy will find a heavy task lies before him; and
it is one to which he will be unable to do justice in a small space,
owing to the variety of matters to be referred to and the necessity
of being particular in regard to each one. In what follows I shall
merely make very brief allusions, as it is hoped the description
already given of past work will be a sufficient guide for the future.
Moreover, those who take up a special branch of inquiry will hardly
rest content with the meagre information usually conveyed in a general
work on astronomy, but will consult those authorities who deal more
exclusively with that branch. Double and binary stars may be said to
form one department, variable and temporary stars another, the colours
of stars a third, while many others may be signified—such as the
determination of star-magnitudes, positions, grouping, and distances;
also the proper motions and number of stars, besides photographic and
spectroscopic work,—each and all of which comprise a field of useful
and extensive inquiry. The amateur will of course choose his own sphere
of labour, consistently with his inclination and the character of his
appliances. In connection with double stars, valuable work yet remains
to be done, though the Herschels and the Struves gathered in the
bulk of the harvest and Burnham has gleaned much that was left. With
regard to bright stars, it may be assumed that very few, if any, close
companions, visible in moderately small glasses, now await discovery,
unless, indeed, in cases where the star forms part of a binary system
of long period, and the epoch of periastron has fallen in recent years.
But with telescopic stars there must be many interesting doubles, some
of them binaries, still unknown. These should be swept up and submitted
Public-domain text, read in full here on John Shaqi.
Reviews
Reviews
No reviews yet
Be the first to share your thoughts on this work.
Elsewhere in the archive
Join the Discussion
Join the discussion
Sign in to leave a comment or review.
Sign InorCreate an account