LACERTA "The Lizard" (pronounced lah-SUR-tah).

Chart showing the constellation.

Lacerta is a small northern and inconspicuous constellation, half immersed in the Milky Way between Cygnus and Andromeda. It is very low or impossible to see for many New Zealanders. (The chart shown is for Auckland. Christchurch astronomers would only see a small amount of the tail.)

The constellation was introduced in 1687 by the Polish astronomer Hevelius, and included 10 stars. Earlier in 1679, Royer had made a figure in this part of the sky, which he called the Sceptre and Hand of Justice, in honour of Louis XIV, but this rather awkward name has now been forgotten, while Lacerta has remained.

To find this constellation look low to the north in the evening sky, and find the bright star Deneb. Look between Deneb and the Great Square of Pegasus. Deneb will not be visible from southern New Zealand, in which case look below and slightly to the left of the great Square.

Chart showing the constellation to the north at its highest. The horizon is for Auckland.

Lacerta chart

Pegasus constellation Pisces constellation Andromeda constellation Cygnus constellation Velpecula constellation Sagitta constellation Delphinus constellation

Some stars in the Constellation.

α Lacertae is a magnitude 3.8 blue-white star, 102 light years away, with a dim companion.

β Lac is a magnitude 4.4 yellow giant star, 170 light years away.

From New Zealand, these two stars are only visible from northern parts of the North Island

Visibility

Lacerta is to the north and highest at about 11 pm (NZDT) at the beginning of October, at 10 pm mid October and 9 pm by the end of the month. By early November it will be lost in evening twilight.

From Auckland, α Lac and, even more so, β Lac skim the northern horizon for an hour or so either side of transit. From the southern half of the North Island they do not rise above the horizon. Only the southern half of the constellation rises a few degrees above the northern horizon for places in the South Island.

MENSA, pronounced MEN-sah,
VOLANS, pronounced VOH-lanz,
HYDRUS, pronounced HY-druss.

Chart showing the 3 constellations.

Two of these constellations, Volans representing the Flying Fish, and Hydrus, the Lesser Water Snake or Sea Serpent, were introduced by the German celestial cartographer Johann Bayer in his famous sky atlas Uranometria in 1603. The constellation Mensa, the Table Mountain (at the Cape of Good Hope) came from the Father of Southern Astronomy Nicolas Louis de Lacaille in the 1750's.

To find these constellations look south in the late summer evening sky, and find Achernar and Canopus. (The Southern Cross points towards Achernar). Look for the cloudy patch like a detached part of the Milky Way between them and slightly lower. This cloudy patch is the Large Magellanic Cloud. The Smaller Cloud is below Achernar. Then use the map.

Chart showing the constellations, high to the south at about 11 pm on January 1, 9 pm February 1

Mensa, Volans and Hydrus.

Constellation Puppis Constellation Pictor Constellation Dorado Constellation Reticulum Constellation Horologium Constellation Eridanus Constellation Phoenix Constellation Tucana Constellation Pavo Constellation Octans Constellation Chamaeleon Constellation Vela Constellation Carina

Details of some of the objects shown in the chart.

α Mensae is a yellow magnitude 5.1 star similar to the Sun, 28 light years away.

β Men is a magnitude 5.3 yellow star 140 light years away.

γ Men is a magnitude 5.2 orange giant star 420 light years away.

 
α Volantis is a magnitude 4.0 yellow star, 78 light years away.

β Vol is a magnitude 3.8 orange giant star, 190 light years away.

γ Vol is a pair of white and yellow stars of magnitudes 3.8 and 5.7, 130 light years away. This pair in a field of scattered stars is an attractive object for small telescopes.

δ Vol is a magnitude 4.0 yellow supergiant star 2400 light years away.

ε Vol is a magnitude 4.4 blue star with a magnitude 8 companion visible in small telescopes. It appears as a bright white gem in a field sprinkled with stars. The primary brighter star also has a very close companion star, with a period of 14.17 days, though it is impossible to see this very close companion in a telescope.

 
α Hydri is a magnitude 2.9 white star, 36 light years away.

β Hyi is a magnitude 2.8 yellow star, 21 light years away.

γ Hyi is a magnitude 3.2 red giant star, 160 light years away

π Hyi is a binocular pair of magnitude 5.5 red and orange unrelated stars. p1 (pi1) lies 400 light years away, while p2 (pi2) is 520 light years away. similar to the Sun.

Visibility

These constellations are all circumpolar for New Zealand and so are visible towards the south at all times of night throughout the year. They are highest during the evening in the Summer months and low above the southern horizon in the Winter.

HYDRA "The Water Snake" pronounced HIGH-druh

Chart showing the constellations.

Hydra The Water Snake, is the largest and longest constellation in the sky, but is not easy to identify because most of the stars are faint. Apart from the brightest star, Alphard, marking the heart of the Water Snake, Hydra's only recognisable feature is its head, which is made up of an attractive group of six stars. Hydra winds its way irregularly from the head near Procyon in Canis Minor, to the tail near Libra and Centaurus.

Hydra is one of the old groups, to which Ptolemy assigned twenty-five stars in all. Hydra is usually identified with the multi-headed monster slain by Hercules, but another legend links it with Corvus the Crow and Crater the Cup, which are found on its (northern hemisphere view) back, the bird having returned to the god Apollo with Hydra in its claws as an excuse for its delayed mission to fetch water in the cup.

Chart showing the constellation.

Hydra and surrounding constellations

Constellation Crux Constellation Centaurus Constellation Lupus Constellation Libra Constellation Virgo Constellation Corvus Constellation Crater Constellation Sextans Constellation Leo Constellation Cancer Constellation Canis Minor Constellation Monoceros Constellation Canis Major Constellation Puppis Constellation Pyxis Constellation Antlia Constellation Vela

Details of some of the objects shown in the chart.

α Hydrae (Alphard, the solitary one) is a magnitude 2.0 orange giant star 130 light years away.

β Hya, is a magnitude 4.3 blue-white star 270 light years away.

γ Hya, is a magnitude 3.0 yellow giant star 105 light years away.

δ Hya, is a magnitude 4.2 blue-white star 140 light years away.

ε Hya, is a beautiful multiple star of contrasting colours. The visible but difficult double stars are yellow magnitude 3.5, and blue magnitude 6.9, but in reality this is a system of five stars.

54 Hya is an easy double star for small telescopes, consisting of yellow and purple stars of magnitudes 5.2 and 7.1, 150 light years away. 54 Hya is in the tail of Hydra, near gamma and R (see next).

R Hya is a crimson-red giant variable star with a period of 387 days. It fluctuates between magnitudes 4 and 10.

U Hya is a deep red carbon star that fluctuates irregularly between magnitudes 4.8 and 5.8.

M 48 (NGC 2548) is a large bright open cluster of about 80 stars, 3000 light years away, just visible to the unaided eye under clear dark skies, but easily seen in binoculars.

M 83 (NGC 5236) is a large face on fine spiral galaxy of 8th magnitude, visible in small telescopes. It has a bright nucleus.

NGC 3242 is a 9th magnitude planetary nebula appearing similar in size to the disk of Jupiter, giving it its popular name "The Ghost of Jupiter". This interesting object lies about 1900 light years away.

Visibility

The great length of Hydra spreads the constellation across nearly 7 hours of right ascension. As a result the head of the constellation, containing eg δ and ε Hya, is due north (for the southern hemisphere) and at its highest nearly 7 hours before the tail, beyond γ and R Hya. By the time the tail is due north, the head of the constellation, which lies nearer the equator, has already set.

In terms of dates and time, α Hya is due north at 9 pm NZST, in early April, as seen from New Zealand, with the tail due north at 2.30 am. It is not until late June that the tail of Hydra is due north at 9 pm. By then α Hya transits at 3.30 pm.

HERCULES, pronounced HUR-kyuh-leez

Chart showing the constellation.

Hercules, the Roman name for the Greek mythological ahero, famous for his twelve labours, is the fifth constellation in order of size. Earlier visualisations were of an anonymous kneeling man, with one foot on the adjacent celestial Dragon, Draco. Some legends identify the constellation with the ancient Sumerian superman, Gilgamesh. The brightest stars are third magnitude and it lies low in the Northern sky for New Zealand observers.

To find the constellation, look low down in the north evening sky to find the bright stars Arcturus and Vega. Locate Hercules using the map. On the chart the horizon is marked for Auckland. Places south of Auckland will see less of Hercules. M 92 lies on the horizon for Invercargill.

Chart showing Hercules as seen to the north at about 11 pm on July 1 or 9 pm on August 1.

Hercules Constellation Serpens Constellation Ophiuchus Corona Borealis Constellation Bootes Constellation Virgo Constellation Lyra Constellation Cygnus Constellation Vulpecula Constellation Sagitta Constellation Aquila

Some stars and interesting objects in the Constellation

α Herculis (Ras Algethi, kneeler's head) is a red super-giant star about 600 times the Sun's diameter. Like most red giants it is an erratic variable fluctuating between magnitudes 3 and 4. It is actually a double star with a magnitude 5.4 blue-green companion, visible in small telescopes.

β Her (Kornephoros) is a magnitude 3.8 white star 140 light years away. It consists of a close pair of stars orbiting one another in about 14 months. A wide 10th magnitude companion is probably not connected with the other two stars.

γ Her is a magnitude 3.7 star nearly 200 light years away. It has a 9.9 magnitude companion 42" from it.

δ Her (Sarin) is a magnitude 3.1 white star 91 light years away. Small telescopes show a magnitude 8.8 star nearby, which is physically unrelated, making this a fine example of an optical double.

ζ Her is a magnitude 3.1 white star 31 light years away, with a close magnitude 5.6 red companion orbiting the primary every 34.5 years. The stars are closest in 2001, but were widest in 1990. Since William Herschel first measured the binary star, more than six complete revolutions have taken place.

κ Her (Marfak) is a magnitude 5.0 yellow giant with a magnitude 6.3 companion easily seen in small telescopes. The pair lie about 280 light years away.

ρ Her is a blue-white magnitude 4.5 star with a magnitude 5.5 companion lying 170 light years away. This is a fine binary for small apertures. The primary is a very close interferometric pair McA 48. 95 Her is a famous pair of stars lying 470 light years away, suitable for small telescopes. A great many double star observers in the 19th Century estimated the colours from "apple green and cherry red" of Piazzi Smith to both pure white. Colour estimates with older refracting telescopes were rather unreliable and the stars appear pale and deep yellow.

95 Her is a pair of 5th magnitude stars with a separation of 6.3". They were first measured by F Struve in 1829. During the 19th century there were reports of fluctating colours, but now they are seen as an identical coloured yellow pair.

M 13 (NGC 6025) is the finest globular cluster available to northern hemisphere viewers. Even at the low altitude southern hemisphere the Great Hercules Cluster is very effective, though not in the same league as omega Centauri or 47 Tuc. The dense broad centre is very bright and sparkling, and the outlying stars cover a diameter greater than the full Moon. It was found by chance by Edmond Halley of comet fame in 1714, and rediscovered by Messier in 1764, although he could see no stars in it, which is a comment on the quality of his telescope. Distance is estimated as 24,000 light years.

M 92 (NGC 6341) is a globular cluster only slightly inferior to its more famous neighbour M 13. It is easily seen in binoculars, though being more condensed, needs a greater aperture than M 13 to resolve its stars. It was discovered in 1777 by J. E. Bode and rediscovered by Messier in 1781, who saw no stars in it. Its distance is estimated as 26,000 light years. NGC 6210 is a 10th magnitude beautiful bluish planetary nebula in an attractive contrast with a number of field stars. It is round and bright with well defined edges. This excellent object for small apertures is enhanced by all types of nebula filters.

NGC 6210 is a planetary nebula, magnitude 9.7 with a bluish disc. It is slightly elliptical,, 20" by 16" with a 12th magnitude central star.

Visibility

Hercules is a large Northern hemisphere constellation, extending from a little north of the celestial equator to just over 50° north. As a result it is never very high from the Southern hemisphere, and the more northerly parts are not visible from the South Island of New Zealand.

α Her is in the more southerly part of the constellation and reaches an altitude of between about 30° and 40° from southern and northern New Zealand respectively. It and δ Her, about 10° lower, are due north and at their highest point in the sky about 11 pm on July 1 and 9 pm on August 1.

GRUS "The Crane", pronounced GRUSS,
MICROSCOPIUM "The Microscope", pronounced My-krah-SKOH-pee-um,
INDUS "The Indian" pronounced INN-duss.

Chart showing the constellations.

Grus is a constellation introduced on the 1603 star atlas of Johann Bayer. It represents a water bird, the Crane, although others have seen the flamingo here. It lies south of the bright star Fomalhaut which is high up slightly east of North mid evening, and is conspicuous because an arc of stars curves toward the second magnitude α Gru.

Microscopium, the Microscope is another of the southern hemisphere constellations representing scientific instruments introduced in the 1750's by the Frenchman Nicolas Louis de Lacaille. It is a small constellation with no conspicuous feature for recognition.

Indus, the American native Indian, was also introduced in Bayer's 1603 star atlas Uranometria. It has no stars brighter than the orange 3rd magnitude α Ind.

To find these constellations look almost directly overhead when looking South. The bright star Fomalhaut will then be very high but just behind you with Grus almost vertically above you at about 10:30 pm at the beginning of October and as soon as it is dark at the end of the month. Microscopium is to the right of Grus and Indus slightly lower to the South.

Chart showing the Constellations as seen high overhead, standing with back to the south at about 11 pm (NZST) mid September or 10 pm (NZDT) mid October.

Grus, Microscopium and Indus.

Constellation Pavo Constellation Tucana Constellation Phoenix Constellation Sculptor Piscis Austrinus Constellation Capricornus Constellation Telescopium Constellation Sagittarius

Some stars in the Constellations

α Gruis (Al Na'ir, meaning the bright one) is a blue-white magnitude 1.7 star, lying 91 light years away.

β Gru, is a magnitude 2.1 red giant star 270 light years away.

γ Gru is a magnitude 3.0 blue-white star 230 light years distant.

δ Gru is an unaided eye double star. The two stars are at different distances and therefore these unrelated stars are an optical double.

μ Gru is a pair of unaided eye stars which appear in the same line of sight by chance.

 
α Microscopii, is a magnitude 4.9 yellow giant star 240 light years away. It has a 10th magnitude companion, visible in small telescopes.

 
α Indi, is a magnitude 3.1 orange giant star 120 light years away.

β Ind, is a magnitude 3.7 orange giant star 270 light years away.

δ Ind, is a magnitude 4.4 white star 110 light years away.

ε Ind is a magnitude 4.7 yellow dwarf star similar to the Sun, but slightly smaller and cooler, lying 11.2 light years away, making it one of the Sun's closest similar neighbours.

θ Ind is a striking pair of stars 91 light years away of magnitudes 4.6 (pale yellow) and 7.0 (reddish), divisible in small telescopes.

Visibility

Parts of one or two of the three constellations pass overhead as seen from all of New Zealand. From the south of the country they constellations are circumpolar so never set. As one moves north so parts of them will briefly be below the horizon when they are at their lowest. As a result the constellations are visible at some time during the night throughout the year, although ther are at their highest in the evening in Spring.

GEMINI (pronounced JEM'n-eye) the Twins

Chart showing the constellation.

This constellation dates from ancient times, representing a pair of twins, the sons of Leda, holding hands. We know these twins as Castor and Pollux, members of the Argonaut's crew. They are half brothers since their fathers were King Tyndareus of Sparta and Zeus, respectively. The twins were the patron saints of mariners, appearing in the ship's rigging as St. Elmo's Fire. In ancient times, Ptolemy assigned eighteen stars to Gemini.

The Geminid meteor shower appears to radiate from a point in near Castor. This shower is one of the richest and most brilliant during the year, reaching a maximum around December 14th.

To find Gemini look north in the late evening sky, and find the bright belt stars of Orion marking the base of the "Pot". Look to the right to find the bright star Procyon in Canis Minor, and then drop down to find the bright pair of Castor and Pollux.

Chart showing Gemini - as seen about 11.00 pm (NZDT) mid February.

The chart shows the horizon from the south of New Zealand. For places further north, the horizon would be lower on the chart, that is the constellations higher. Some stars hidden for southern observer, would be just above the horizon for more northerly observers.

Gemini. 9.7 kb

Constellation Eridanus Constellation Orion Constellation Monoceros Constellation Hydra Constellation Sextans Constellation Leo Constellation Cancer Constellation Canis Minor Constellation Leo Minor Constellation Lynx Constellation Auriga Constellation Tuarus

Details of some of the objects shown in the chart.

α Geminorium, Castor is an astounding multiple star of six components. To the unaided eye it appears as a blue-white magnitude 1.6 star 52 light years away, but a small telescope will split this into two close components of magnitudes 2.0 and 2.9, which orbit each other in 467 years. Both stars are spectroscopic binaries, and small telescopes show a 9th magnitude red dwarf companion, which is itself an eclipsing binary star.

β Gem, Pollux at magnitude 1.1, is the brightest star in the constellation despite being "beta". This is mainly because Johann Bayer, who labelled the stars with Greek letters in 1603, did not carefully distinguish which was the brighter star of the "Twins". Pollux is 33.7 light years away.

γ Gem, is a magnitude 1.9 blue-white star 105 light years away.

δ Gem is a creamy-white star of magnitude 3.5 with a reddish magnitude 8.1 companion. The contrast between the brighter and faint companion make the pair difficult in small apertures. The brighter star is a spectroscopic binary with a 6.13 year period.

ε Gem is a magnitude 3.0 yellow supergiant star 903 light years away. Powerful binoculars or a small telescope reveal a 9th magnitude companion.

ζ Gem is both a variable star and a binocular double star. The yellow super-giant star is Cepheid variable 1170 light years away, fluctuating between magnitude 3.7 and 4.1 every 10.2 days. Binoculars or small telescopes reveal a wide 8th magnitude unrelated companion star.

η Gem is 349 light years away and another double variable star. This red giant star fluctuates in a semi-regular manner between magnitudes 31 to 3.9 every 230 days. It has also a close 8th magnitude companion, requiring a large aperture telescope to distinguish it from the glare of the primary star. The primary star is a spectroscopic and occultation binary with a period of 8.17 years.

κ Gem is a magnitude 3.6 yellow giant star 143 light years away, with a magnitude 9.5 companion star difficult in small telescopes because of the brightness contrast.

ν Gem is a blue-white star 503 light years away with a wide 9th magnitude companion.

38 Gem is a beautiful double star for small telescopes, shining like gems in a field sown with scattered stars. Its white and yellow components are of magnitude 4.7 and 7.6 lying 1500 light years away.

M 35 (NGC 2168) is a large bright star cluster visible to the unaided eye from a dark sky site. Binoculars or small telescopes at low magnification show the 200 or so stars that make up this cluster to be in curving chains. It lies about 2600 light years away.

NGC 2392 is a large moderately bright 8th magnitude planetary nebula, known as the Eskimo or Clown Face Nebula, because of its appearance in large telescopes or photographs. Small telescopes show it as a fairly large rounded blue-green disc. Its central star is of 10th magnitude.

Visibility

Gemini is north of the equator so fairly low for New Zealand observers. The centre of the constellation is due north at about 10.00 pm (NZDT) in mid of February. The brightest star, Pollux, β Gem, is due north about an hour later. For New Zealand viewers, with the Sun setting earlier during the following three months, Pollux will remain visible as soon as the sky is dark after sunset. It will be to the north during March and early April, but will gradually move round to the north-west and get lower during the rest of April and May.

DORADO pronounced doh-RAH-doh

Chart showing Dorado

This constellation representing the Goldfish or Swordfish, was introduced by the German celestial cartographer Johann Bayer in his famous sky atlas Uranometria in 1603.  The constellation came from the vivid imagination of the Dutch explorer Pieter Dircksz Keyser, who noted them on a voyage to the East Indies (now Indonesia) in 1596.

To find Dorado look south in the late summer evening sky, and find Achernar and Canopus. (The Southern Cross points towards Achernar).  Look for the cloudy patch like a detached part of the Milky Way between, and slightly lower than, them.  This cloudy patch is the Large Magellanic Cloud.   The Smaller Cloud is below Achernar.

The chart shows the sky looking a little east of south at about 11.30 pm (NZDT) in mid December

Chart of Dorado and surrounding sky.

Constellation Caelum Constellation Horologium Constellation Eridanus Constellation Phoenix Constellation Reticulum Constellation Hydrus Constellation Tucana Constellation Mensa Constellation Octans Constellation Pictor Constellation Carina Constellation Volans

Details of some of the objects shown in the chart.

α Doradus is a magnitude 3.3 blue-white star about 190 light years away.

β Dor is yellow super-giant about 7,500 light years away.  This star is one of the brightest Cepheid variable stars pulsating between magnitudes 3.8 and 4.7 every 9 days and 20 hours.

The most famous object in Dorado is the Large Magellanic Cloud.  This satellite companion galaxy to our own Milky Way is easily visible to the unaided eye from a dark sky site on a moonless night as a cloudy patch.  This irregular spiral galaxy is around 180,000 light years away, but binoculars and telescopes show individual bright stars, fuzzy nebula and clusters.  The cloud also extends into part of the constellation of Mensa.

NGC 2070 the celebrated Tarantula Nebula is a looping cloud of hydrogen gas about 1000 light years in diameter in the Large Cloud that appears to the unaided eye as a fuzzy star, also known as 30 Doradus.  Through a telescope the spider like shape becomes apparent.  At the centre of the nebula is a cluster of bright supergiant stars whose ultra-violet output makes the nebula glow.  The Tarantula Nebula is larger and brighter than any other nebula in the Milky Way.  If it were at the distance of the Orion nebula,  the Tarantula would fill the entire constellation of Orion and would cast shadows.


Visibility

Dorado is highest in the sky to the south between 10 and 11 pm NZDT in mid January. The constellation is far enough south to be circumpolar for much of New Zealand, only the most northerly part briefly sets as seen from Auckland.

DELPHINUS (pronounced del-FIE-nes), the Dolphin
EQUULEUS (pronounced eh-KWOO-lee-us), the Little Horse

Chart showing the constellations.

Delphinus, the Dolphin originated in ancient Greek times and celebrates the long standing relationship between man and the most intelligent of sea creatures. Ptolemy assigned 10 stars to it. In legend dolphins were the messenger of the sea god Poseidon, and were credited with saving the life of Poseidon's son, Arion, when he was attacked on a ship. The constellation has a distinctive shape, with its four main stars forming a rectangle known as Job's Coffin. Its two brightest stars are called Sualocin and Rotanev, which backwards read Nicolaus Venator, the Latinized form of the Name Niccolo Cacciatore, who was assistant to the Italian astronomer Guiseppe Piazzi.

Equuleus, the Little Horse or Foal, seems to have originated by Hipparchus about 150 BC, for some small stars near Delphinus. Ptolemy, four centuries later only assigned four stars to it. One myth sees it as Celeris, the brother of neighboring Pegasus.

To find these constellations look north in the evening between the Great Square of Pegasus and the bright star Altair. Delphinus is the easiest to see with its distinctive shape.

Chart showing the constellations as seen to the north at about 9.30 pm (NZST) mid September.
The horizon is for southern New Zealand

Delphinus and Equuleus.

Scutum constellation Serpens constellation Ophiuchus constellation Hercules constellation Lyra constellation Cygnus constellation Vulpecula constellation Sagitta constellation Aquila constellation Aquarius constellation Capricornus constellation Pisces constellation Pegasus constellation

Some stars and interesting objects in the Constellations

α Delphini (Sualocin) is a magnitude 3.8 blue-white star 241 light years away.

β Del (Rotanev), is magnitude 3.5 white star 97 light years away.

γ Del is a beautiful bright pair of stars, making an attractive sight for small aperture telescopes. It consists of golden and yellow-white stars of magnitudes 4.3 and 5.2, 101 light years away. In the same field of view is a fainter double star Struve 2725, consisting of stars of 7th and 8th magnitude.

 
α Equulei (Kitalpha, little horse) is a magnitude 3.9 yellow giant star 186 light years away.

γ Equ is a slightly variable white star of magnitude between 4.58 and 4.77, 115 light years away. There is also a close faint companion, which is not easy to see.

ε Equ appears to be a triple star 197 light years away in telescopes. The orbit of the close yellow pair is near to the line of sight with a period of 101 years. The stars are now closing and more difficult to separate. There is a wider third star, easily seen. The brightest star is actually a spectroscopic binary star with a period of 2.03 days, so in reality this is a quadruple star system. The star is also known as 1 Equ.

Visibility

Delphinus and Equuleus are some 10° north of the equator so achieve a moderate altitude in New Zealand. They are visible from April, in the pre-dawn morning sky to the north-east through to October when they are visible to the north-west after evening twilight.

The constellations are due north and at their highest at about 9.30 to 10.00 pm NZST in mid September, an hour later at the beginning of the month and an hour earlier by October 1

CYGNUS, the Swan. (Pronounced SIG-nuss)

Chart showing the constellations.

This is one of the larger of the old constellations, to which seventeen stars were assigned by the Greek astronomer Ptolemy in 150 AD.  It represents a swan flying down the Milky Way.  There are many legends about swans, including that of Zeus who visited Leda, wife of King Tyndareus of Sparta disguised as a swan.  This mating resulted in Pollux, one of the heavenly twins.  Cygnus has also been identified with Orpheus, who was turned into a swan and placed next to his harp (Lyra) in the sky.  The Arabs depicted this constellation as a hen.

Difficult to see from New Zealand is the Veil Nebula, the remains of a star that exploded as a supernova around 60,000 years ago.  Cygnus also contains a bright X-ray source Cygnus X-1, that is probably matter from an accretion disc spiralling into a black hole.

To find this constellation look low to the north in the evening sky, and find the bright star Deneb.  Deneb will not be visible from southern New Zealand, in which case look below a position between the bright star Altair in Aquila, the Eagle, and the Great Square of Pegasus, for the large cross shape going into the horizon.

The northern hemisphere's "Summer Triangle" is marked by the bright stars Altair, Vega and Deneb.

Chart showing Cygnus as seen on the northern horizon, mid September about 10 pm.
The levels of the horizon at Auckland, Wellington and Invercargill are shown.

Cygnus chart

Hercules constellation Lyra constellation Aquila constellation Vulpecula & Sagitta Ophiuchus & Serpens Delphinus & Equuleus Pegasus constellation Andromeda constellation Lacerta constellation Aquarius constellation Capricornus constellation Microscopium constellation Piscis Austrinus Sculptor constellation Cetus constellation Pisces constellation Sagittarius constellation Scutum constellation

Some stars and interesting objects in the Constellation

α Cygni (Deneb, meaning tail) is a magnitude 1.3 blue-white super giant star 3229 light years away.

β Cyg (Albireo) is one of the sky's showpiece double stars.  It consists of two gloriously contrasting yellow and blue-green stars, the brighter is a yellow giant of magnitude 3.1, while the companion is of magnitude 5.1.  They can be separated through good binoculars, and are a beautiful sight in amateur telescopes. The 3.1 yellow star is 386 light years away.  The bright star is also a close pair of stars but these are unlikely to be resolved in amateur telescopes.

γ Cyg (Sadr, breast) is a magnitude 2.23 yellow supergiant star 1524 light years away.

δ Cyg appears a magnitude 2.9 bright pale yellow star, but actually is a pair of stars, difficult to resolve because they are very low for New Zealand.  They lie 171 light years away.

ε Cyg (Gienah, wing) is a magnitude 2.46 yellow giant star 72 light years away.

μ Cyg is a bright yellow pair of stars, first measured in 1780 by William Herschel, the discoverer of Uranus.  The star magnitudes are 4.83 and 6.22 and they orbit each other about every 700 years.  They lie 73.1 light years away.  The stars require a moderate telescope to split them.  There is a wide unrelated 7th magnitude binocular companion.

ο1 Cyg (31 Cyg) may be the most beautiful binocular double in the sky, consisting of orange and turquoise companion stars of magnitudes 3.8 and 4.8, 1353 light years away.  It is very low and difficult from New Zealand.

61 Cyg is a famous star.  It was the first star to have its parallax measured, by the German astronomer Wilhelm Bessel in 1838.  This is the slight difference in position of the star compared to background stars from opposite sides of Earth's orbit.  It is a nearby star 11.4 light years away, consisting of a pair of stars with magnitudes 5.2 and 6.05.

M 39 is a large bright open cluster discovered in 1764 by Messier.  It needs a large field and low magnification to be seen properly, and is suitable for binoculars and small telescopes, although it is very low even for north New Zealand stargazers.

NGC 7000, the well-known very large "North American" nebula is 3° east of Deneb, in the rich Cygnus region of the northern Milky Way.  If it were higher it would be easy to see in binoculars or a rich field telescope.

Visibility

Cygnus only partly rises as seen from New Zealand. At its highest, the brightest star Deneb, is about 8° above the horizon as seen from Auckland and less than 4° from Wellington. Places further south than latitude 45° will not see the star rise at all. From Auckland the star is above the horizon for nearly 6 hours, but only 4 hours from Wellington.

Deneb is due north from Auckland and Wellington at about 11.30 pm (NZST) mid August, 9.30 pm mid September and 8.30 pm (NZDT) in mid October. After mid October evening twilight will prevent observation of the constellation.

CRUX, pronounced CRUCKS, the Southern Cross

Chart showing the constellation.

Crux, the Southern Cross, is the smallest constellation in the sky, but one of the most celebrated. The early Portuguese navigators saw it as a symbol of their faith, and the mystery of the unknown lent it an additional charm in the minds of those from whom the southern skies were hidden. There are other cross patterns formed by stars, but the distinguishing feature of the two bright pointers alpha and beta Centauri make Crux unmistakable.

Crux lies in a dense and brilliant part of the Milky Way, which makes the famous dark nebula known as the Coalsack striking in silhouette against the star background. This is the head of the Emu to the native aborigines of Australia. The rest of the Emu is made from the dark lanes in the Milky Way.

From New Zealand latitudes Crux is circumpolar and always in the sky, rotating about the south celestial pole each day.

Chart showing the constellation orientated as seen about 8.30 pm mid May

Crux and surrounding constellations

VARIABLE stars are shown as open circles.  DOUBLE stars are shown with a bar through their circle.

Constellation Musca Constellation Carina Constellation Chamaeleon Constellation Lupus Constellation Vela Constellation Centaurus

Some stars and interesting objects in Crux

α Crucis (Acrux) appears to the unaided eye as a star of magnitude 0.9 but small telescopes show it to be a close double star with blue-white components of magnitudes 1.4 and 1.9.  Acrux is the 12th brightest star in the sky.
An unrelated star, magnitude 4.8, about 1.5 arc minutes from Acrux, is easily seen as separate in binoculars.

β Cru, is a magnitude 1.3 blue-white star 570 light years away. It is a variable star fluctuating by less than 0.1 magnitudes every 6 hours.

γ Cru, is a magnitude 1.6 red giant star 88 light years away. There is a very wide magnitude 6.4 companion, which is unrelated, visible in binoculars.

δ Cru, is a magnitude 2.8 white star 470 light years away. It is the faintest of the four main stars of the "Cross".

ε Cru, is a magnitude 3.6 yellow star, 125 light years away.

ι Cru is a magnitude 4.7 orange star 280 light years away. This has a wide magnitude 7.8 companion star, visible in small telescopes.

μ Cru is a pair of blue-white stars of magnitudes 4.0 and 5.2, able to split by the smallest of telescopes or even good binoculars.

NGC 4755 (κ Crucis) is an open cluster of stars popularly known as the "Jewel Box", from Sir John Herschel's vivid description of the cluster as a "casket of variously coloured precious stones". It is rich and bright with the stars showing delicate colours accentuated by an orange-red supergiant. It can easily be seen by the unaided eye as a star, and indeed was originally catalogued as such in pre-telescope times.

The Coalsack is a large irregular dark nebula lying nearby at a distance of around 550 light years. It is a cloud of dark gas and dust.

Visibility Crux is visible all the year from New Zealand. It is at its highest at about 9.30 pm in mid May, when the long axis will "point" straight down towards the celestial south pole.

In general Crux is highest during the evening in the early and mid winter months. It is low above the southern horizon in the evening soon after sunset in early summer.