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A new star atlas for the library,
the school, and the observatory

Richard Anthony
Proctor, Thomas William Webb



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^.■■



;■.., }X



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A NEW STAE ATLAa



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LONDON: PBIVTSD BY

SPOTTIBWOODK AND 00., NBW-STIIKBT aQDAUK

AHU PAALIAUBKT 8TUKBT



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■■



A NEW STAR ATLAS



THE LIBRARY, THE SCHOOL, AND THE OBSERVATORY.

IN TWELVE CIRCULAR MAPS

(WITH TWO CmSX PLATK8).

INTENDED AS A COMPANION TO
'WEBB'S CELESTIAL OBJECTS FOB COMMON TELESCOPES.*

WITH A LETTERPRESS INTRODUCTION ON THE STUDY OF THE STABS,
ILLUSTRATED BY SEVERAL WOODCUTS.



EICHARD A. PEOCTOR, B.A. Camb.

HON. 8EC. E.A.S.

ADTHOB OF ^THB SUN,' 'OTHER WORLDS THAN OURS,' • SATURN AND ITS SYSTEM,'

*A NiEW LARGE STAR ATLAS,' * THE ONOMONIG STAR ATLAS,'

' THE HANDBOOK OF THE STARS,' ETC.



* Why did not aomebody teach me the ConstellatioTis, and make
me at home in the starry heavens, which are always overhead,
and which I don't half know to this day f ' Carltlb.



SB3C01TD SZ>ITIO IN".



LONDON:
LONGMANS, GEEEN, AND CO.

1872.



All rights reserved. ^ t

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PREFACE.



This Atlas is reduced from my large Star Atlas*
The plan on which it has been constructed — briefly
described in the accompanying letterpress — needs
no special discussion here ; because I have already
fully dealt with it in the introduction to the large
Atlas. I may remark, however, that the present
work affords new and striking evidence of the advan-
tages of the plan; for we have here a little book
which can be carried in the pocket, while the small
Atlas published by the Society for Diffusing Useftd
Knowledge is printed on sheets about sixteen inches
square ; and yet the scale of the accompanying maps
is larger than that of the S.D.TJ.K. Atlas. The re-
daction in size is gained chiefly by a reduction in
the distortion of the maps, the maximum expansion
due to this cause being fifty-eight times greater in
the S.D.TJ.K. maps than in the present (see note at
pp. 11, 12). Moreover, the twelve maps of this
Atlas overlap, a fifth part of the heavens being in-
cluded in the overlaps ; so that each of the twelve
maps exhibits a tenth part of the heavens.



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vi PREFACE.

No pains have been spared to clear the maps of all
which could cause conftision to the beginner; but
this has been done in such a way that the more
advanced student may find nothing wanting. For
example, the meridians and parallels are drawn in
to every fifteenth, instead of every fifth degree (as
usual) ; but, since all the intersections of these lines
to every fifth degree are marked in the maps (with a
small cross), the places of stars can be determined,
from catalogues or the like, as readily as though the
lines themselves were marked in. In like manner all
the longitude and latitude lines, except the ecliptic
and the solstitial colures, are omitted; but their
intersections to every fifteenth degi'ee are marked
(with a small dotted cross), and any student who is
sufficiently advanced to require these lines will be
able to recognise very readily where they lie, or to
pencil them in if need be. I consider their omission,
and the omission of all but every third of the me-
ridians and parallels usually introduced, to be abso-
lutely essential for the convenience of the majority
of those who will use these maps ; though the maps
would, undoubtedly, be imperfect if the position of
these lines were not indicated.

The method of indicating the effects of precession
is also novel. Instead of a precession-triangle iu the
<5omer of each map, with instructions for obtaining
<5ompass measurements, I have placed precession-
arrows over the maps (always on latitude-parallels,
15% 30°, &c.) ; and these show at once by what amount



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PREFACE, vii

stars in the neighbourhood are precessionally dis-
placed in one hundred years. In passing, however,
let me call the student^s attention to the fact (often
forgotten) that the stars suffer no real displacement,
and that he will do well to regard the effects of
precession as shifting the meridians and parallels
bodily in a direction contrary to that indicated by
the arrows.

The constellation boundaries are somewhat darker
than I would have had them if I had not had to con-
sider the requirements of beginners. It seems to me
very necessary that the extent of each constellation
should be recognisable at a glance (at least by most of
those who will use these maps). Indeed, if no other
means would suffice for this, the spaces should be
coloured as in geographical maps. I think the pre-
sent arrangement meets all requirements.

As to the constellation-figures, I conceive that few
will be disposed to regret their omission from the
present Atlas. The old usage — by which a star's
place was indicated by a reference to the club of
Orion, or the northern claw of the Crab, or the
southern wing of the Virgin, and so on — ^is happily
falling into disuse ; and, as the number or letter of a
star is always mentioned, even by those who employ
the ancient practice, no difficulty can ever arise in
finding any star referred to.**^

* In my Gnomonic Atlas the figures are shown. The plates belonging
to that atlas fonn the index plates of my large atlas, and can also ^e
obtained separately.



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viii PREFACE.

It is of more importance to notice that the present
Atlas is specially intended to serve as a companion
to Mr. Webb's excellent treatise, * Celestial Objects
for Common Telescopes.' With a very few excep-
tions, all the objects mentioned in that work are
shown in this Atlas. The exceptions relate to objects
(some twenty in all, perhaps) which could not be
introduced without overcrowding. To make up for
these omissions, however, several hundreds of objects
not included in Mr. Webb's charming work are
shown in this Atlas. Thus, all the objects in Admiral
Smyth's * Celestial Cycle,' all the binary stars in
Mr. Brothers's catalogue, all the Bed Stars in
Schjellerup's catalogue,^ all the nebulae down to
the order marked ^ very bright ' in Sir J. Herschel's
great catalogue, are introduced here, with only
such exceptions (perhaps a score in all) as were
necessary to avoid overcrowding. It is hoped that,
with this unusual richness in objects of interest, the
Atlas will prove a complete vade mecum for the
amateur telescopist.

I have to thank Mr. Webb for the careful revision
of the Atlas, so far as the objects to be included in



* Some of these stars would appear to be variable in coloar ; at least
Mr. Webb and other careful observers do not recognise any ruddiness
in certain stars included in Schjellerup's catalogue. Such stars are
marked * Bu ?' The student should notice, also, that the catalogue is
incomplete, many red stars having been noted since it was drawn up.
Furthermore, many of the stars included in the catalogue are not pro-
perly speaking red, but may rather be described as orange or ruddy
yellow.



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PREFACE. ix

his treatiBe are concerned. In the course of this
revision he has noticed several discrepancies between
the constellation outlines in this work (based on
the British Association CataJogue) and those used
in Smyth's * Bedford Cycle.' As Mr. Webb's ' Celes-
tial Objects ' is closely associated with the * Cycle,'
he has not thought it desirable to remodel the
arrangement of the constellations ; and, on the other
hand, as this Atlas is a miniature of my ^ New Star
Atlas,' I should hare been unwilling to change the
constellation outlines, even if I did not entertain the
opinion that Baily's changes result in an immense im-
provement. The student will therefore be prepared
to find that some few objects described in * Celestial
Objects ' as in one constellation are here shown in
another; and even that some constellations men-
tioned in * Celestial Objects' (as Antinous, Anser,
Clypeus, &c.) are here omitted altogether. But no
difficulty need arise on this account, because Mr.
Webb in every case mentions the right ascension and
declination of the several objects.

The letterpress introduction has been prepared for
the use of beginners, who often find it difficult to
compare the heavens with the maps of a star-atlas.
I would recommend, as a convenient supplement to
the information contained in these pages, my work
entitled the * Half-Hours with the Stars,' published
by (and the property of) my friend Mr. Hardwicke,
of Piccadilly. Its twelve maps show how the stars are
placed, night by night and hour by hour, throughout



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X PBEFACE.

the year in England. Thus they serve a purpose
wholly distinct from that of such a star-atlas as the
present. Each work is, however, complete in itself;
and, as the ^ Half-Hours with the Stars ' suffices to
teach the merest beginner the names and places
of all the leading star-groups, so the present will
enable the learner to identify all the stars of the
first five orders of magnitude ; that is, all the stars
except the faintest of those seen on very dark and
clear nights.

EICHAED A. PEOCTOK.

Bbiohton: December 1871.



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CONTENTS.



•o»



PAGE

The Starey Heavens sttbround va like a Hollow Globe . 1

This Globe seemingly tubns bound an Axis .... 2

General effects of this turning 3

Its rate . . . ' 4

Kesultino movements of the Stars easily recognised in a

FEW minutes •*>

'The Star-sfhbrb rotates 366 times (roughly) in a year . 6

Plan on which the present Atlas pictures the Heavens . 7

Use OF THE Index Maps .13

How TO COMPARE THE MaPS WITH THE HeAVENS . . .11

Tables I. and II., showing where the Stars in each Map are

TO BE looked FOB AT DIFFERENT HOURS AND SEASONS . . 20

Table III., showing what Constellations are visible in
England, and in what part of the Sky, at different

HOURS AND seasons 22

Table IV. — List of Constellations (Latin and English names),
with the Map in which each Constellation is to be

FOUITD 24

Table V. — List of Star-names 26



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xii COyTENTS.



LIST OP WOODCUTS.

VTOS. PAOK

1 AND 2. D1AO&A.IC8 ILLU.STBATIKO CONSTRUCTION OF AtlAS 9

3 AND 4. „ „ „ „ . . 10

6 AND 6. „ „ „ „ . . 11

7. Showing whbbb thb Bears, Pointers, &c., are to

bb looked for at different hours and seasons 15

8 AND 9. Showing TrrwARDS what parts of the Sky the Stars

IN THE SBVEBAL MaPS OF THIS AtLAS ARE TO BE
LOOKED fOR AT DIFFERENT HOURS AND SEASONS 18, 19



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HOW TO LEARN THE STARS.



On a clear, but dark night, we see many hundreds of stars of
various orders of brightness. Those who are but beginning
the study of the heavens are impressed with the feeling that
it must be a very difficult task to become familiar with all the
star-groups, and to learn the names of the brighter orbs. The
task appears yet harder when they are told that the stars seen
on one night or at one hour are not the same as those seen on
other nights or at other hours — that the aspect of the starry
heavens is in fact continually changing. Yet nearly all wish
to know the stars, even though they may not wish to engage
in the actual study of astronomy. In reality, it is by no
means so difficult as might be supposed to recognise all the
chief star-groups — or constellatitms, as they are called— and
to learn the names of all the leading stars. One may, without
much trouble, become so wsU acquainted with the stars as to
be able to recognise even three or four seen through a break
in a cloudy sky. I propose now to show how such knowledge
is to be gained.

In the first place, the student must learn what is the true
arrangement of the stars as distinguished from that which he
sees at any instant from some standpoint on the earth. He
views the heavens as a dome, or hollow half-globe, on the
inside of which the stars are spread in hundreds. But he
must remember that beneath the horizon there is another
similar half-globe, passing right round under his feet, and
similarly bespread with stars. If the earth were perfect I if
transparent, and the light rj the sun were lost^ thv obsei^cr on

B



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2 A NEW STAR ATLAS.

earth would find himself placed seemingly at the centre of a
vast hollow globe covered with stars. And if he could con-
tinue to watch this globe hour after hour, day after day, and
year after year, he would find that all the stars* kept their
places on the globe, but that the globe itself seemed to turn
bodily round, as if on an axle passing through his own position.
There would be a ceaseless and perfectly uniform turning
round of the sphere of stars, but in other respects there would
be no perceptible change in the position of any of the stars.

The earth not being transparent, we see at night but one
half of this rotating sphere ; and the light of the sun being
sufficient to obliterate that of the stars, we cannot in the day-
time see the sphere of stars at all. But the learner must
remember that one and the same star-sphere surrounds him on
all sides, below as well as above the horizon, and at all hours,
by day as well as by night. It is because the stars do not
change in their position on this sphere that they are called fixed
stars. Their fixity enables ua to recognise the groups which
they seem to form. A well-marked group of stars, once re-
cognised, cannot easily be forgotten ; and it becomes thence-
forth a sort of sky mark whence the learner can proceed to
other groups. And as there are certain star-groups which al-
ways continue above the horizon, the observer who has learned
to recognirte some of them, can on any clear night extend his
survey from these known groups to others that are unknown.

It is easy to see why some groups are never carried below
the horizon, notwithstanding the continual rotation of the star-
sphere. Two points of the turning sphere are necessarily
fixed. These are called the poles of the celestial sphere. In
England one of these poles — the north pole of the heavens —
lies due north, and rather more than halfway above the
horizon, towards the point overhead (called the zenith). The
other point is, of course, below the horizon, due south, and
rather more than halfway down towards the point directly
under the observer (called the nadir). If the observer laces

* The light of the sun being obliterated, neither the moon nor anj
of the planets \?ould be visible.



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MOW TO LEARN THE STARS. 3

due south, the stars near the horizon on his left hand, or towards
the east, have lately risen, and are passing higher; those near
the horizon on his right hand, or towards the west, are about to
pass below the western horizon. Those which rise above the
horizon nearly due east, will pass higher and higher till
they are due south, when they will be rather lees than half-
way from the southern horizon towards the point overhead.
Thence they will descend imtil they are nearly due west, when
they will pass below the horizon. If the observer, having
duly recognised the nature of this motion (which corresponds
exactly with the seeming motion of the sun on a spring or
autumn day), remembers that it is brought about by the rota-
tion of the whole sphere of the stars, he will at once see what
must be the nature of the stellar motions in other parts of
the heavens. He will see that stars which rise on any part of
the horizon from east to south will follow a similar course, but
shorter and shorter the nearer their place of rising is to the
south point ; their elevaticm when due south will also be less
and less ; and they will follow a descending course precisely
resembling their ascending course, setting just as far to the
west of the south point as they rose to. the east of it. A star
which is on the horizon when due south can only be seen for
a minute or two, just grazing the southern horizon. Stars
which rise in any part of the horizon from east to north, will
also continue to pass higher and higher till they are due south,
following a longer and longer course, the nearer their place of
rising is to the north point ; their elevation when due south
will also be greater and greater ; and they will follow a de-
scending course precisely similar to their ascending course,
netting just as far to the west of the north point as they rose to
the east of it. A star which is on the horizon when due north
performs a complete circuit before it again reaches the horizon,
when it is due north as before ; its highest point being reached
when due south after half a circuit, at which time it is but
about thirteen degrees from the point overhead. No stars
irithin the circuit of such a sfcir ever reach the horizon at all.
Each performs a complete circuit, which is smaller and smaller

B 2



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4 A NEW STAR ATLAS.

the nearer the star is to the pole of the heavens. A star
which, when due north, is about 13 degrees above the horizon,
is almost exactly overhead when half a circuit has been com-
pleted. Stars nearer to the pole than this are due north when
at their highest in their circuit as well as when at their lowest.

But let the student bo reminded that all these varieties of
motion are the effects of but one single turning movement.
He must not suffer himself to be confused by these motions as
described (I have, however, described them as clearly as I
could) ; but if he finds doubt arising in his mind, when he is
actually studying the stars, let him fiice due north, and, look-
ing towards the north pole of the heavens (a point rather more
than halfway above the northern horizon towards the point
overhead)^ let him remember that the stellar sphere moves as
though turning bodily round on an axiSj — running from that
pole through his own station {which is at the centre of the
sphere) to a point directly opposite . the former, — the rotation
being such that stars near the pole move round it in a direc-
tion contrary to that in which the hands of a watch move. It
will serve equaUy well if he faces due south, and remembers
that the stellar sphere is being carried round from left to right, as
though on an axis passing through his station and the invisible
pole (which lies below the southern horizon, and rather more
than halfway down towards the point directly beneath him).

The rate at which the stellar sphere rotates must next be
considered.

Roughly speaking, the sphere of stars may be said to turn
round once in each day ; but in reality it turns rather more
quickly, so as to make one complete rotation in about four
minutes less than a day. Thus a star which rises in the east
takes six hours (less about one minute) to reach the highest
part of its path, when it is due south ; and it takes the same
interval in passing to its setting- place in the west. It is, there-
fore, twelve hours above the horizon. Stars whose place of
rising lies nearer the south are less than twelve houi*s above
the horizon. Stars which rise to the north of the east point are
more than twelve hours above the horizon. Stars which touch



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HOW TO LEARN THE STARS. 5

or pass above the northern horizon take twenty-four hours (less
about four minutes) in circling round the pole of the heavens.
It 18 well to remember that the resulting motion of the stars
can be easily recognised in a very few minutes. This may be
shown in a variety of ways. If a star is seen above or beside
some distant object, as a tree or house, then if the student re-
main in an unchanged position for a few minutes only, he will
see that the star has perceptibly changed its place. If the
star is towards the east, it seems to have moved upwards and
towards the right. If it is towards the west, it seems to have
moved towards the right, and downwards. If it is towards
either the south or the north, it seems to have moved horizon-
tally towards the right. (All stars near the horizon move to-
wards the light, though only those towards the north and
south move horizontally.) Ten minutes will produce an un-
mistakable change of place.*

* It is strange how little familiar most persons are with the fact that
the stellar motions are thus obvious. The notion seems to prevail that
onlj the astronomer in his protracted night-watching can become cogni-
zant of the stellar motions. One of the most beautiftd and touching
descriptions in all Dickens's works — the death of Stephen Blackpool, in
Hard Tiines — is somewhat impaired by the introduction of an im-
possible star, shining for hours down the deep chasm into which the
poor fellow had fallen. The month of the Old Hell Shaft was so
narrow a chasm as to be concealed by tall grass. St4=%phen fell far down ;
and the star was so bright that he could show it to Rachael among all the
other stars visible on an autumn night. Certainly no such star existii' in
the catalogues of astronomers. It is probable, however, that Dickens
may have heard some such stoiy about a bright star — Venus or Jupiter
— only the star cannot have been seen just overhead. Novelists and
poets sometimes introduce astronomical details rather unhappily. One
has made the new moon rise at one o*clock in the morning ; another
makes midnight moonless though the moon had risen at eleven ; in the
* Portent * (a tale which appeared in one of the early numbers of the Cor»-


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Online LibraryRichard Anthony ProctorA new star atlas for the library, the school, and the observatory: in twelve ... → online text (page 1 of 7)