Z Hydrae Magnitude

features of interest

BETA (P) monocerotis 5 One of the finest triple stars in the sky for small telescopes, consisting of an arc of three 5th-magnitude stars.

EpsiLON (e) monocerotis 5 A double star-on some charts labeled 8 Monocerotis—with components of 4th and 7th magnitudes.

M50 K 5 An open cluster about half the apparent size of a full moon, visible in binoculars but requiring telescopes to resolve individual stars.

NGC 2244 K 5 S A group of stars of 6th magnitude and fainter, visible through binoculars. The cluster is surrounded by the Rosette Nebula.

NGC 2264 K 5 S Another combination of open cluster and nebula. Photographs and CCD images show a surrounding nebulosity into which protrudes a dark wedge known as the Cone Nebula.

Hydra Hydrae (Hya)

width llllll depth lim size RANKING 1st fuLLY vislBLE 54°n-83°s

Hydra is the largest of the constellations, stretching more than a quarter of the way around the sky from the top of its head, south of the constellation Cancer, to the tip of its tail, between Libra and Centaurus. For all its size, there is little within Hydra to catch the eye other than a group of six stars of modest brightness south of Cancer that forms its head. Its brightest star is Alphard, magnitude 2.0, whose name, coined by Arab astronomers, means "the solitary one," in reference to its position in an area of sky with THE water no other prominent stars. Hydra represents the multi- snake headed monster fought and killed by Hercules in the second of his labors, although it is depicted as a single-headed water snake.

southern hemisphere

the head of hydra

The most easily recognizable part of Hydra is its head, formed by six stars. The brightest of these are Epsilon (e) Hydrae (top center) and Zeta (Z) Hydrae (top left), both of third magnitude

THE GHosT of JupiTER

As its name suggests, this planetary nebula is a much fainter object than upiter. Small telescopes show it as a blue-green ellipse, but larger apertures are needed to see the inner ring and the central white dwarf.

M83 spiRAL GALAxY

M83, on the border of Hydra and Centaurus, is visible in small telescopes. Amateur CCD images, such as this one, bring out the pink clouds of gas dotted along its spiral arms where stars are forming.

M83 spiRAL GALAxY

M83, on the border of Hydra and Centaurus, is visible in small telescopes. Amateur CCD images, such as this one, bring out the pink clouds of gas dotted along its spiral arms where stars are forming.

THE GHosT of JupiTER

As its name suggests, this planetary nebula is a much fainter object than upiter. Small telescopes show it as a blue-green ellipse, but larger apertures are needed to see the inner ring and the central white dwarf.

features of interest alpha (a) HYDRAE (AlpHARD) 2 An orange-colored giant, the brightest star in Hydra.

EPsiLoN (e) HYDRAE 5 A close binary star with components of contrasting colors, requiring apertures of at least 3 in (75 mm) and high magnification to be separated. The yellow and blue component stars are of 3rd and 7th magnitudes and have an orbital period of nearly 1,000 years.

R HYDRAE 2 1 5 A red giant variable of the same type as Mira that ranges in brightness between 3rd and 11th magnitudes every 13 months or so.

M48 H 5 An open star cluster larger than the apparent size of the Moon, well seen through binoculars and small telescopes.

M83 5 S An impressive face-on spiral galaxy. Through small telescopes, it appears as an elongated glow, but larger apertures reveal its spiral structure and a noticeable central bar, possibly similar to the bar that is thought to lie across the center of our own Milky Way Galaxy. M83 lies about 15 million light-years away.

NGC 3242 (THE ghost of JUPITER) 5 S A relatively prominent planetary nebula. It shows a disk similar in apparent size to the planet Jupiter when seen through small telescopes, hence its popular name, the Ghost of Jupiter.

Antlia Antliae (Ant)

width mm depth l size RANKING 62nd fuLLY vislBLE 49°n-90°s

This faint constellation of the southern sky consists of a handful of stars between Vela and Hydra. It was one of the constellations introduced in the mid-18th century by the French astronomer Nicolas Louis de Lacaille to commemorate scientific and technical inventions, in this case an air pump used for experiments on gases.

the air pump features of interest

ZETA (Z) antliae 1 5 A multiple star that appears as a wide pair of 6th-magnitude stars when viewed through binoculars. A small telescope reveals that the brighter of the pair has a 7th-magnitude companion.

NGC 2997 5 S This elegant spiral galaxy is just too faint to be seen well in small telescopes but is captured beautifully on photographs and CCD images.

spiral galaxy NGC 2997

This galaxy is inclined at an angle of about 45° to our line of sight. Photographs and CCD images show pinkish clouds of hydrogen along its spiral arms.

southern hemisphere

Sextans Sextantis (Sex)

width l depth l size ranking 47th fully visible 78°n-83°s

This faint and unremarkable constellation lies on the celestial equator, south of Leo. it was introduced in the late 17th century by the Polish astronomer Johannes hevelius. it represents a sextant, the kind of instrument

This faint and unremarkable constellation lies on the celestial equator, south of Leo. it was introduced in the late 17th century by the Polish astronomer Johannes hevelius. it represents a sextant, the kind of instrument

southern hemisphere used by Hevelius himself for measuring and cataloging the positions of stars in the sky features of interest

17 and 18 sextantis 1 A line-of-sight double formed by two unrelated stars of 6th magnitude, shown neatly by binoculars.

NGC 3115 (THE spindle GALAXY) 1 5 A highly elongated lenticular galaxy that has acquired its popular name on account of its shape. Lying about 30 million light-years away from the Earth, it is detectable through small to medium-sized telescopes.

Crater Crateris (Crt)

width l depth l size RANKING 53rd fuLLY vislBLE 65°n-90°s

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