Follow the Arc to a Pulsar!

   During Spring in the northern hemisphere, the seven bright stars that form the Big Dipper are easily seen high over the northern horizon. Located at the hindquarters of the Great Bear (Ursa Major), this asterism (group of stars) has long been used as a celestial guide by travelers. During the American Civil War, slaves memorized a song called “Follow the Drinking Gourd” that helped them locate the stars that would point their way to freedom. By walking in the direction of the ‘drinking gourd’ stars the escaping, freedom seeking slaves, would be following a northerly route taking them away from the slave states to the free states to the north, or to Canada.
   There is an ‘old’ Astronomical saying, a sort of memory aid, for finding at least two constellations by way of their alpha, or brightest star in their respective constellation. In Bootes the Herdsman there is the orange-reddish star Arcturus, and in Virgo the Harvest Maiden the bluish-white star Spica. The saying – “follow the arc to Arcturus, then speed to Spica” is how you connect these two stars with the curve, or arc, in the handle of the Big Dipper.
   Simply look toward the northeast to find the 7 stars making up the Big Dipper. Then look for the curved handle and follow the arc or curved handle toward Arcturus and then continue on to Spica. This is typically done during the Northern Hemisphere spring and summer season when Bootes and Virgo are in the evening skies.
   While you are looking toward this region of the sky, you can also investigate some of our neighboring solar systems.
   Scientists now believe that two sunlike stars in this region have at least one orbiting satellite each, and that a nearby pulsar could have up to three satellites. Just below the bowl of the Big Dipper lies 47 Ursa Majoris, a star with an orbiting object estimated to have two to three times the mass of Jupiter and a revolution rate of 1103 Earth days. Near the northern boundaries of Virgo, an object orbiting around 70 Virginis is estimated to have six to seven times the mass of Jupiter and a revolution rate of 117 Earth days. Although the objects themselves are too far away to be seen, the suns around which they orbit are visible to the naked eye.
   A third solar system you could direct your attention to is also within the boundaries of Virgo. Unlike the other two solar systems, the objects in this system orbit a pulsar, PSR 1257+12. A pulsar is a small, extremely dense, and rapidly rotating neutron star, a remnant of a massive star that has collapsed into itself following a supernova event. PSR 1257+ 12 gets its name from its celestial coordinates, 12 hours 57 minutes right ascension and 12o north declination. This pulsar is one of at least several known pulsars in our galaxy and this one has an estimated diameter of 16 km, and a mass that is one to two times that of our Sun.
pulsar   Pulsars earn their name from the radio waves they emit, which we receive in regular pulses. Pulsars emit radio waves as a narrow beam, much like the beam of light emitted from a lighthouse. Just as direct light from a lighthouse sweeps past a point regularly, so does the beam of radio waves emitted from a pulsar. PSR 1257+ 12 emits radio waves that reach the Earth with at an interval of 6.2 milliseconds. Because we receive pulsed radio waves from a pulsar as a result of its rotation, we know a pulsar’s pulse interval coincides with its period of rotation. This means that PSR 1257 + 12 rotates every 6.2 milliseconds!
kepler   Exo-solar systems and their planets have been detected through various methods with the greater majority of these exo-solar systems being discovered by the Kepler orbiting observatory. To date more than 1,000 objects have been confirmed as an exo-planet, with more than 4,600 objects waiting confirmation.
distant-worlds-cover   Download a series of monthly star maps and data pages. Each monthly star map shows the location of many of the stars we know or are reasonably certain that are stars with their own planets. Click here to download the “Where Are the Distant Worlds Star Maps”. (2-3 Mb PDF)

   
   
   
   
   
   
   
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Caution: Objects viewed with an optical aid are further than they appear.
Click here to go to the Qué tal in the Current Skies web site for more observing information for this month.

Name A Planet

   An organization with goals for enhancing/enriching (my words) space exploration, research, and education, Uwingu, has just released their first product with a focus on the many exo-planets discovered so far, and those yet to be discovered. While not actually a product in the physical sense it is an attempt to raise funding for use as grant money in the coming months. Grant applications will become available early next year with funds raised through this product. So in order to raise funding the public is encouraged to propose a planet name to be added to a database of possible names to be used for the many exo-planets being discovered. Each name nominated, or each vote cast for a name costs $0.99 (99 cents).
   Keep in mind that while this database of names will be made available for Astronomers to choose from, whatever name or names one proposes are not official names, nor is it implied that they are official names, unlike the ‘name a star‘ scams. The naming of celestial objects is the the responsibility of the International Astronomical Union (IAU).
   Also on the web site are, under the Educate link, are some resources relevant to the search for exo-planets and are arranged by grade level.

   Click here to read a short story about how Uncle Ron and Aunt Nan learned about naming stars.

Click here to go to the Qué tal in the Current Skies web site for more observing information.

Planets Buzzin’ in the Beehive

Artwork of Planets in Beehive Cluster

NASA Astronomers have just announced that they have found planets orbiting Sun-like stars in the Beehive Cluster, (M-44). These planets are being described as a ‘hot Jupiter’ meaning that they are large like Jupiter, composedof gases, but closer to their star than the planet Mercury is to the Sun.
The Beehive Cluster is an open-star cluster within the constellation of Cancer the Crab. Both of which rise before sunrise. The Beehive Cluster is visible as a smudge of light to the naked-eye and through binoculars or a telescope using a low-power eyepiece appears as a nice sprinkling of stars. The planet Venus just recently passed close to M-44 as I had recently posted.

Be sure to visit the Plane Quest web site where you will find a lot of information about the Planet Quest project like 3,130 exo-planets have been discovered so far, although not all have been confirmed.
For the educator there are several interactives where you and students could design a planet for example.