March
Puppis
Puppis was originally part of a larger constellation named Argo~Navis, the. Argonaut's ship from Greek mythology. For convenience Argo Navis was was subdivided into smaller constellations by the French astronomer, Nicholas Louis de Lacaille in the 1750s. It is now, Puppis the Poop or Stern, Carina the Keel, Vela the Sail, and Pyxis the Compass. When the division took place the stars retained their original designations, hence Puppis does not contain an A]pha or Beta, both of these now belong to Carina. The three brightest stars of Puppis, Zeta (2.25 magnitude), Pi (2.7) and Rho (2.8)
Culminating at 9pm late February, Puppis offers some of the best southern objects for binoculars and small telescopes. With the Milky Way running through the constellation, it abounds with bright stars, open clusters and double stars and is a good region for bmoculars there are at least 25 open star clusters (three of which are Messier objects. M46, M47 and M93) and many of these are well suited for small apertures.
M46,
also known as NGC2437, is an excellent open cluster ot about two hundred
stars forming arcs and lines, fifty of which can be seen in a small telescope
with low power. A small annular planetary nebula (NGC2438) lies to the
north of centre, and can be seen in 150mm to 200mm instruments. The nebula
is not associated with the cluster, being ,about twice the distance away.
Just 1.5 degrees to the west is M47 (NGC2422), a cluster that contrasts
strongly with M46. M47 has about twenty five stars of magnitude 6 and fainter,
that form an attractive uneven scattering of bright and faint suns. Two
orange 8 th magnitude stars rnake a nice contrast with the predominantly
blue and white population. M47 even has two double stars in its ranks,
Struve 1121 and 1120, both easy in small telescopes. Within 5 degrees of
the constellations brightest star Zeta, three more open clusters can be
located NGC245 1, NGC2477 and NGC2546.
Puppis
has so many good open clusters, it ls difficult to pick the best, however
NGC2477 is hard to beat, a real gem. It is 25 arc minutes across and condensed
toward the centre, with the stars forming gentle curved arcs and lines.
With about half the population of three hundred 11th magnitude stars condensed
within a 12 arc minute ball, it looks like a loose globular cluster.
Aside from the many open clusters Puppis has one
globular cluster, and a few galaxies. Considering its position within the
Southern Milky Way , it is not surprising that galaxies are so few. It
also comes as no suprise that the constellation abounds in double and multilple
stars. Burnham's Celestial Handbook lists over 125 of them. Many of these
objects are truly superb and we will only mention a few of the easiest
and best ones for small telescopes.
NGC 2451 is an open cluster in Puppis. Discovered
by Giovanni Batista Hodierna in 1654. It consists of 40 stars, the brightest
of which is a yellowish giant of magnitude 3.6 c puppis, this cluster is
quite close to us only about 850 light years.
There
is also an odd nebulous object in Puppis designated as NGC 2467.
Within this gaseous 4 arc minute diameter envelope
lies the stars that excite the nebula causing it to glow. One of these
stars appears to be a protostar (known to astronomers as Herbig-Haro objects)
with an unusual jet of gas emanating from it. The jet can be seen with
a 30cm or larger telescope under dark skys (away from city lights).
k Puppis; an excellent yellow pair of almost equal 4.5 magnitude.
Dunlop 30 ) (also Rumker 65); a fine pair of unequal magnitude, yellow and red.
Sigma Puppis; 3rd and 8th magnitude stars orange and white.
Dunlop31; an orange and white pair in good field, 5th and 8th magnitude
Interesting facts:
1) Ranked 20th in size.
2) Has no Messier objects.
3) One of 14 constellations invented by Lacaille during his stay at Cape of Good Hope between 1751-1752.
Information supplied by
Quasar Publishing.
P.O Box 85
Georges Hall. NSW 2198