USING THE FAIRFAX COUNTY PUBLIC SCHOOLS (FCPS) STARFINDER

A planisphere, or starfinder, is a star map on a rotating disk or "wheel" that enables you to see which stars and constellations will be visible in the night sky for any date and time during the year. Set the date and time by turning the star disk so that the month (e.g., JAN, etc.) is aligned with the arrow above the word DATE on the western horizon; dates are for the middle of the month (e.g., 15 January) at 9:00 p.m. The southern sky is shown on the front of the starfinder; the northern sky is shown on the back. The horizon is the imaginary horizontal line where the sky appears to meet the land (note that horizon is the base word in horizontal). The zenith is the imaginary point in the sky directly overhead an observer; on the FCPS Starfinder, the zenith is at the top of the star disk.

CONSTELLATIONS

The FCPS Starfinder shows 22-or-so of the most recognizable constellations, which include many of the brightest stars in the night sky. On both sides of the starfinder, the table CONSTELLATIONS lists the names of the star groups shown on the starfinder. In the blank space to the left of each name, write the number (shown on the star disk) that matches the name of the constellations listed in the table. Refer to the following alphabetical lists that correllate constellation name and number.

Southern Sky (front of starfinder) Number Constellation Number Constellation Number Constellation 17 Andromeda 6 Corvus 1 Orion 12 Aquila 14 Cygnus 16 Pegasus 7 Bootes 15 Delphinus 10 Sagittarius 2 Canis Major 3 Gemini 9 Scorpius 11 Capricornus 5 Leo 4 Taurus/Pleiades 8 Corona Borealis 13 Lyra Aries

Northern Sky (back of starfinder) Number Constellation 3 Cassiopeia 4 Cepheus 5 Draco 1 Ursa Major 2 Ursa Minor

SEASONAL & CIRCUMPOLAR CONSTELLATIONS

Like the Sun (which is a star), most stars appear to rise in the east, move across the southern sky, and set in the west (as shown by the arrows on the southern side of the star disk, labeled "APPARENT MOTION OF THE STARS"). Most constellations in the southern sky are "seasonal," that is, they are visible at night for six months during the year.

In the northern sky (shown on the back of the starfinder), some stars always remain in your field of view, that is, appear above the horizon, every night of every day of the year. These star groups are known as the Circumpolar Constellations because they appear to circle Polaris, the North Star (Letter "D," northern side of starfinder).

BRIGHT STARS

On the starfinder, brighter stars appear as larger dots. Star names are listed in the table BRIGHT STARS on both sides of the starfinder. Set the starfinder for 9 p.m. on January 15; observe that Sirius (Letter "A," southern side of starfinder), the brightest star in the night sky, is located in the constellation Canis Major, the Big Dog (No. 2).

MAJOR METEOR SHOWERS

Have you ever seen a "shooting star?" Shooting stars are actually meteors--small pieces of Solar System debris, usually sand-sized particles, that vaporize while colliding at great speed (up to 40 miles per second) with the Earth's atmosphere. Annual "meteor showers" (up to several meteors per minute) occur when the Earth's orbit crosses the orbits of comets. Most annual meteor showers are named for the constellation from which the meteors appear to radiate. The table of MAJOR METEOR SHOWERS (which appears on both sides of the starfinder) lists most of the annual meteor showers, including well-known meteor showers such as the Perseids, Leonids, and Geminids.

WHAT THE FCPS STARFINDER DOESN'T SHOW

RELATED RESOURCES

• Fairfax County Public Schools Planetarium Web site: http://www.fcps.k12.va.us/DIS/OHSICS/planet/index.htm
• Sandburg Center for Sky Awareness, a Fairfax County Public Schools Planetarium: http://www.wsanford.com/~wsanford/exo.html
  1. FCPS Starfinder (print using 65 lb. cover stock)
     1. Star Wheel - Southern Sky (Adobe Acrobat PDF, 30K)
     2. Star Wheel - Northern Sky (Adobe Acrobat PDF, 11K)
     3. Overlay Sheet (Adobe Acrobat PDF, 55K)
  2. A Skywatcher's Pronunciation Guide (stars & constellations): http://www.wsanford.com/~wsanford/exo/pronunciation_guide.html
  3. Constellation of the Month (CoM): http://www.wsanford.com/~wsanford/exo/com.html
  4. Constellations of the Zodiac: http://www.wsanford.com/~wsanford/exo/b-w_zodiac.html
• Skymaps.com (more detailed sky map): http://www.skymaps.com/
• Smithsonian National Air and Space Museum Albert Einstein Planetarium - Weekly Skywatcher's Report (narrative): http://www.si.edu/resource/faq/skywatch.htm