it is not greatly inferior to 47 Tucanae, though it is less than
half the size.
Pavo, the Peacock, has one bright star, ·, which can be
found by using ·Centauri and ·Trianguli Australe as
pointers; indeed, this is perhaps the best way of leading
into the region of the Birds. ·has no proper name, and
is rather isolated from the rest of the constellation; it is of
type B, 230 light-years away and 700 times as luminous as
the Sun.
ÎPavonis is a short-period variable with a range of
from magnitude 3.9 to 4.7 and a period of just over 9 days;
suitable comparison stars are Â(3.96), Á(4.22), ̇(4.01),
Í(4.36) and Ó(4.64). (Avoid Ï, which is itself a variable
of uncertain type; the same comparison stars can be used.)
ÎPavonis is of the W Virginis type and much the brightest
member of the class. It was once known as a Type II
Cepheid, but a W Virginis star is much less luminous than
a classical Cepheid with the same period, and Îis no more
than about four times as luminous as the Sun; its distance
is 75 light-years.
The fine globular cluster NGC6752 (C93) lies not far
from Ï. It is easy to see with binoculars, and is moderately
condensed; the distance is about 20,000 light-years. It
seems to have been discovered by J. Dunlop in 1828.
Indusis a small constellation created by Bayer in 1603;
its brightest star, ·, forms a triangle with ·Pavonis and
Alnair in Grus. There is nothing here of immediate interest
for the telescopic observer, but it is worth noting that
ÂIndi, of magnitude 5.69, is one of the nearest stars – just
over 11 light-years away – and has only one-tenth the
luminosity of the Sun, so that it is actually the feeblest star
which can be seen with the naked eye.
If it could be observed from our standard distance
of 10 parsecs (32.6 light-years), its apparent magnitude
would be 7, and it would be invisible without optical aid.
It is of type K, and orange in colour. Despite its low lumi-
nosity, it may be regarded as a fairly promising candidate
for the centre of a planetary system.
Microscopiumis a very dim constellation adjoining Grus
and Piscis Australis. It was formerly included in the
Southern Fish, so that Áwas known as 1 Piscis Australis
and Âas 4 Piscis Australis. It contains nothing of special
note. ·is an easy double (magnitudes 5.0 and 10.0, separ-
ation 20.5 seconds, position angle 166 degrees). There
are also two Mira variables which can reach binocular
visibility at maximum. U ranges from magnitude 7 to 14.4
in a period of 334 days, while S ranges between 7.8 and
14.3 in 209 days. Like most Mira stars they are of spectral
type M, and are obviously orange-red.
Microscopium was one of the numerous constellations
introduced by Nicolas-Louis de Lacaille in his famous
maps of the southern sky in 1752, but frankly it seems
unworthy of a separate identity.
Sculptoris another one of Lacaille’s groups; originally
Apparatus Sculptoris, the Sculptor’s Apparatus. It occu-
pies the large triangle bounded by Fomalhaut, Ankaa in
Phoenix, and Diphda in Cetus, but the only objects of
interest are the various galaxies.
NGC253 (C65) lies almost edgewise on to us, and lies
not far from ·, close to the border between Sculptor and
Cetus; it is a favourite photographic target. NGC55 (C72)
lies near Ankaa on the border between Sculptor and
Phoenix, and seems to be one of the nearest galaxies
beyond the Local Group, lying at no more than 8 million
light-years from us. Like NGC253 it is a spiral, seen
almost edge-on; it is easy to identify and attractive to pho-
tograph. The south galactic pole lies in Sculptor, and the
whole region is noticeably lacking in bright stars.STAR MAP 21
Microscopium, Sculptor
BRIGHTEST STARS
Star R.A. Dec. Mag. Spectrum Proper name
hm s ° ‘ “
· 22 08 14 46 57 40 1.74 B5 Alnair
‚ 22 42 40 46 53 05 2.11 M3 Al Dhanab
Á 21 53 56 37 21 54 3.01 B8
 22 48 33 51 19 01 3.49 A2
Also above magnitude 4.3: È(3.90), ‰^1 (3.97), ‰^2 (4.11), ̇(4.12), ı(4.28)
VARIABLES
Star R.A. Dec. Range Type Period Spectrum
hm °’ (mags) (d)
^122 22.7 45 57 5.4–6.7 Semi-reg. 150 S
S2 2 26.1 48 26 6.0–15.0 Mira 401 MBRIGHTEST STARS
Star R.A. Dec. Mag. Spectrum Proper name
hm s ° ‘ “
· 00 26 17 42 18 22 2.39 K0 Ankaa
‚ 01 06 05 46 43 07 3.31 G8
Á 01 28 22 43 19 06 3.41 K5
Also above magnitude 4.3: ̇(3.6, max), Â(3.88), Î(3.94), ‰(3.95).
VARIABLES
Star R.A. Dec. Range Type Period Spectrum
hm °’ (mags) (d)
̇ 01 08.4 55 15 3.6–4.4 Algol 1.67 BB
SX 23 46.5 41 35 6.8–7.5 ‰Scuti 0.055 A–FBRIGHTEST STARS
Star R.A. Dec. Mag. Spectrum Proper name
hm s ° ‘ “
· 22 18 30 60 15 35 2.86 K3
Also above magnitude 4.3: ‚(3.7, combined), Á(3.99), Í(4.23).
DOUBLES
Star R.A. Dec. P.A. Sep. Mags
hm °’ ° “
‚ 00 31.5 62 58 169 27.1 4.4, 4.8; B is a close
binary (444y)
Î 01 15.8 68 53 336 5.4 5.1, 7.3
CLUSTERS AND NEBULAE
MCNGC R.A. Dec. Mag. Dimensions Type
hm °’ ’
00 53 72 50 2.3 280 160 Galaxy; Small
Cloud of
Magellan
106 104 00 24.1 72 05 4.0 30.9 Globular cluster;
47 Tucanæ
104 362 01 03.2 70 51 6.6 12.9 Globular clusterBRIGHTEST STARS
Star R.A. Dec. Mag. Spectrum Proper name
hm s ° ‘ “
· 20 25 39 56 44 06 1.94 B3
‚ 20 44 57 66 12 12 3.42 A5
Ï 18 52 13 62 11 16 3.4 (max) B1
Also above magnitude 4.3: ‰(3.56), Ë(3.62), Î(3.9 max), Â(3.96), ̇(4.01), Á(4.22).
VARIABLES
Star R.A. Dec. Range Type Period Spectrum
hm °’ (mags) (d)
Î 18 56.9 67 14 3.9–4.7 W Virginis 9.09 F
Ï 18 52.2 62 11 3.4–4.3 Irregular – B
SX 21 28.7 69 30 5.4–6.0 Semi-reg. 50 M
CLUSTERS AND NEBULAE
MCNGC R.A. Dec. Mag. Dimensions Type
hm °’ ’
93 6752 19 10.9 59 59 5.4 20.4 Globular clusterBRIGHTEST STARS
Star R.A. Dec. Mag. Spectrum Proper name
hm s ° ‘ “
· 20 37 34 47 17 29 3.11 K0 Persian
Also above magnitude 4.3: ‚(3.65).The brightest star is Á: R.A. 21h 01m 17s.3, dec. 32° 5’ 28”, mag. 4.67. It was formerly known as
1 Piscis Australis.The brightest star is ·: R.A. 00h 58m 36s.3, dec. 29° 21’ 27”, mag. 4.31.
VARIABLES
Star R.A. Dec. Range Type Period Spectrum
hm °’ (mags) (d)
S0 0 15.4 32 03 5.5–13.6 Mira 365.3 M
R0 1 27.0 32 33 5.8–7.7 Semi-reg. 370 N
CLUSTERS AND NEBULAE
M C NGC R.A. Dec. Mag. Dimensions Type
hm °’ ’
72 55 00 14.9 39 11 8.2 32.4 6.5 SB galaxy
65 253 00 47.6 25 17 7.1 25.1 7.4 Sc galaxy
70 300 00 54.9 37 41 8.7 20.0 14.8 Sd galaxyGRUSPHOENIXTUCANAPAVOMICROSCOPIUMSCULPTORINDUSGb Atl of Univ Phil'03stp 2/4/03 7:43 pm Page 259