Pictures in the Sky
How to Use This Section

Pictures in the Sky contains information about the constellations of the sky and their stars. Information is also presented about the various deep sky objects such as galaxies, nebulae, and star clusters they contain. The constellations are organized by pages according to the time of the year in which they are most visible. Each of the constellations is presented in a format like the one shown below:
  Hercules Hercules the Strongman  

Pronunciation:  (HER-ku-leez) 
Abbreviation:  Her   Genitive:  Herculis
Right Ascension:  17.33 hours   Declination:  29.90 degrees
Area in Square Degrees: 
Crosses Meridian:  9 PM, July 25

Hercules is best seen during the summer in the northern hemisphere. You can find it by looking between Draco and Ophiuchus. Hercules is visible in the southern hemisphere from May until August. The constellation was named after the son of Zeus, who defeated the Nemean Lion, Leo, and the many-headed beast called Hydra. While fighting Hydra, he also killed the little crab, Cancer.

Points of Interest in Hercules
Diagram of the constellation Hercules Object Name Type/Translation V Mag
1 M92 Globular Star Cluster 6.4
2 M13 Globular Star Cluster 5.8
3 Rasalgethi "Head of the Kneeling One" 3.48
4 Kornephoros "Club-bearer" 2.77
5 Sarin * 3.14
6 Marfik "Wrist" 5.00
7 Maasym * 4.41
8 Kajam "Club" 4.57

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The top of each listing shows the constellation name and its symbol. Immediately below that are a few lines of important information as follows:

Pronunciation:  Shows the correct pronunciation of the constellation in phonic form. Clicking on the "Play Audio" button will play an audio file of the correct pronunciation.

Abbreviation:  The standard abbreviation for the constellation name. This is the name that often appears on star charts and planishperes.

Genitive:  This is the gentitive form of the constellation name. The gentitive is used to indicate possession. In the case of a constellation, the gentitive form of the name is used when referring to the brightest stars in the constellation. These stars are listed alphabetically using the Greek alphabet. For example, the first star in the constellation Hercules is known as Alpha Herculis. The next star is Beta Herculis followed by Gamma Herculis and so on. 

Right Ascension:  The right ascension is the amount of time that passes between the rising of Aries and another celestial object. Right ascension is one unit of measure for locating an object in the sky and is indicated in hours.

Declination:  The declination is the angular distance of the object in the sky from the celestial equator. Declination is the second unit of measure for locating an object in the sky and is indicated in degrees.

Area in Square Degrees:  This is the total area that the constellation occupies in the sky, expressed in units of square degrees. The celestial sphere of the sky is divided into 360 equal parts. One of these parts equals one degree.

Crosses Meridian:  This is the date and time that the constellation crosses the meridian. The meridian is an imaginary circle drawn through the North and South poles of the celestial equator.

The next section shows a drawing of the constellation as well as a listing of all objects of interest. Please note that these images only show the brightest stars in the constellation. Because of this, the images may not represent the entire picture that the constellation suggests. Extremely dark skies are needed to see all of the faint stars that complete the entire picture. The listing next to the image includes Messier Objectsand named stars. An * will appear in a column if the information is unavailable or does not exist.

Object Number:  Reference numbers on the drawings are used to locate the objects on the list. Messier objects are shown with a blue reference number in the list. Stars are shown with a green reference number.

The Type/Translation:  This column gives information about each object. For Messier objects, the Type/Translation column will show the kind of object. This is usually a galaxy, star cluster, or nebula. For stars, the Type/Translation column will show the translation of the star's name. The names of most stars are derived from words in ancient languages such as Greek, Roman, or Latin.

Vmag:  This is the visual magnitude of the object. Visual Magnitude is a scale used by astronomers to measure the brightness of a star or other celestial object. Visual magnitude measures only the visible light from the object. On this scale, bright objects have a lower number than dim objects.

You may click on the Return to Top of Page link to return to the menu at the top of the page. The constellations are arranged by the months in which they are best visible. You may use the menu at the top to navigate forward to the next month or backward to the previous month.

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