Tuesday 19 September 2017 - 22:34:56 Posted by  Bobby

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 Night Skies of May

  Lengthening twilight can make early evening observing more difficult in northern latitudes, where the sparkling stars of winter are being replaced by those of summer. In the Southern hemisphere, this is the best time of year to see Crux (the Southern Cross) and its "pointers" Alpha and Beta Centauri.

 Top 2 Constellations For May

 Hercules (The Warrior)


 Mythology of Hercules

Hercules is a large but not prominent constellation depicting the hero of Greek Myth, Hercules lies between the bright stars Arcturus and Vega. The body of Hercules is inverted in the sky, the head being marked by Alpha Herculis, in the south, and the feet by the stars to the north. Hercules was ordered by King Eurystheus of Mycenae to perform 12 labors, one of which was to slay a dragon (marked by adjacent Draco). Hercules is depicted resting on his right knee, with his left foot on the dragon's head. The constellation features the brightest globular cluster in northern skies, M13, and some notable double stars. Its brightest star is Beta Herculis, magnitude 2.8.

 The Facts

  • Depiction: Hercules
  • Pronounced: HER-kyou-leez
  • Genitive: Herculis
  • Abbreviation: Her
  • Highest in the Sky: June to August
  • Size Ranking: 5th
  • Coverage Area: 1,125 Sq. Degrees
  • Right Acension: 17 hours
  • Declination: 30°
  • Visibility: 90°N to 39°S

 Notable Objects

  • Alpha Herculis: Double star
  • Rho Herculis: Optical Double star
  • M13: Hercules Cluster
  • The Propeller: Multiple star system
  • M92: Globular cluster
  • NGC 6207: Spiral galaxy
  • NGC 6210: Planetary nebula
  • 95 Herculis: Red giant star

 Named Stars

  • Ras Algethi, Alpha Herculis
  • Rutilicus, Beta Herculis
  • Sarin, Delta Herculis
  • Marfik, Kappa Herculis
  • Maasym, Lambda Herculis
  • Kajam, Omega Herculis

 Best Viewed Objects/Stars

Alpha Herculis (Rasalgethi)

 A red giant of variable brightness. It ranges between 3rd and 4th magnitudes, with no set period, as a result of fluctuations in its size. A small telescope shows a companion of magnitude 5.4. Hercules is depicted kneeling, and the name Rasalgethi is derived fron an Arabic term meaning "the kneelers head."

Rho Herculis

 A optical double star. The two components of magnitudes 4.6 and 5.4 can be separated with a small telescope with high magnification.

95 Herculis

 A silver and gold pair of stars of magnitudes 5.0 and 5.2, divisible through a small telescope.

100 Herculis

 A pair of almost identical white stars, both of magnitude 5.8, that can be separated with a small telescope. The two stars do not form a true binary.


 The brightest globular cluster in the northern sky. Under dark skies, it appears to the naked eye like a hazy star. Binoculars show it clearly, about half the apparent size of the full Moon, and a small telescope shows its brightest stars. It is 25,000 light-years away.


 A globular cluster, fainter and smaller than M13 but still worthy of attention. Binoculars are needed to find it, and a telescope of moderate aperture will show its stars.

 Virgo (The Virgin)


 Mythology of Virgo

Virgo is the largest constellation of the zodiac and the second largest of all the constellations. It lies on the celestial equator between Leo and Libra. The constellation is usually identified as Dike, the Greek goddess of justice, or sometimes as Demeter, the corn goddess. Virgo is of particular interest because it contains the nearest large cluster of galaxies, the Virgo Cluster. The Sun passes through the constellation from September 16th to October 31st.

 The Facts

  • Depiction: The Virgin
  • Pronounced: VER-go
  • Genitive: Virginis
  • Abbreviation: Vir
  • Highest in the Sky: April to June
  • Size Ranking: 2nd
  • Coverage Area: 1,294 Sq. Degrees
  • Right Acension: 13 hours
  • Declination:
  • Visibility: 74°N to 74°S

 Notable Objects

  • M58: Barred spiral galaxy
  • M61: Barred spiral galaxy
  • M84: Elliptical galaxy
  • M86: Elliptical galaxy
  • M87: Elliptical galaxy
  • M90: Spiral galaxy
  • M104: Sombrero Galaxy

 Named Stars

  • Spica, Alpha Virginis
  • Zavijah, Beta Virginis
  • Porrima, Gamma Virginis
  • Auva, Delta Virginis
  • Vindemiatrix, Epsilon Virginis
  • Heze, Zeta Virginis
  • Zaniah, Eta Virginis
  • Syrma, Iota Virginis

 Best Viewed Objects/Stars

Alpha Virginis (Spica)

 The brightest star in Virgo and, at magnitude 1.0, among the 20 brightest in the sky. It is a blue-white star, 260 light-years away. Spica is Latin for "ear of wheat," an object Virgo holds in her left hand.

Gamma Virginis

 A binary star. To the naked eye it looks like one star of magnitude 2.7. In fact, there are two yellow-white stars (both of magnitude 3.5) orbiting a common center of mass every 169 years. This motion affects the binary' appearance significantly. In 2005, when the stars were closest together as seen from Earth, an aperture of 10 in (250 MM) was needed to divide them. After that they moved rapidly apart. Currently the stars are divisible with a small aperture and will remain that way for the rest of the century.


 A famous giant elliptical galaxy near the center of the Virgo Cluster. It is probably the easiest member of the cluster to see through a small telescope.

M104 (The Sombrero Galaxy)

 A spiral galaxy that appears almost edge-on to us and looks elongated when seen with a small telescope. Larger apertures show a dark lane of dust in the spiral arms, crossing the central nucleus of stars. The galaxy is not part of the Virgo Cluster but lies somewhat closer to us.

The Virgo Cluster (The Virgo-Coma Cluster)

 A Cluster of 2,000 or more galaxies about 50 million light-years away that extends from Virgo into Coma Berenices. Its brightest members, notably the elliptical galaxies M49, M60, M84, M86, and M87, are visible with the size of telescope used by amateur observers.

 Features of Interest (April/May)

 Alpha Centauri (Centaurus)

  A mere 4.4 light-years away, this is the closest star to the Earth after the Sun. A small telescope reveals two yellow stars, the brighter of which is similar in temperature and brightness to the Sun. A third member of the family, Proxima Centauri, is much fainter.

 Mizar (Ursa Major)

  The second star in the handle of the Big Dipper known as Mizar or Zeta Ursae Majoris, is a wide double. Its companion, Alcor, is visible to the naked eye, while a small telescope shows another star, closer to mizar.

 Omega Centauri (Centaurus)

  The largest and brightest globular cluster in the sky, also called Omega Centauri, is visible to the naked eye as a hazy star. It is clear through binoculars, & a small telescope shows the brightest of its 100,000 or more stars.

 The Big Dipper (Ursa Major)

  The familiar shape of the Big Dipper (Plough), formed by seven stars in Ursa Major is a prominent site in northern skies in spring. The second star in the handle, called Mizar, has a fainter partner, visible to observers with normal eyesight.

 Meteor Shower Activity

May Meteor Showers
(The Eta Aquarids)
  These fast moving, bright meteors, caused by dust from Halley's Comet, radiate from a point near the water jar in Aquarius, and are best seen from southern latitudes. Activity begins in late April, peaks at about 35 meteors an hour in the first week of May, and ends in late May.

 Also Visible This Month

 Where to?

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