Winter is Coming

   It is still summer in the northern hemisphere and we are still more than a month away from the September equinox however take a look toward the eastern horizon some morning before sunrise and you will see some of the familiar constellations of the winter season (northern hemisphere) rising and coming into view. In this group of constellations is the Gemini Twins, and at their feet is the 25-day old waning crescent Moon.
   Near the Moon, within about 5o, is an open star cluster, M-35. This is a 5th magnitude collection of stars located about 2500-3000 light years from the Earth. M-35 is not, as some may think, a 2.5 ton U.S. Army all terrain truck.

   
   
   
   

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.

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.

Batter Up!!

   Wednesday March 25th the 5.5 day old waxing crescent Moon is in the region of the sky between the horns of Taurus the Bull and the upraised club over Orion’s head, in Orion’s hand. This is a familiar part of the sky to many as within the sky around the Moon’s location include more of the brightest stars (1st magnitude or brighter) than any other part of the sky or other season.

   However this is spring time (in the northern hemisphere) and spring time is synonymous with Baseball. So at times like Wednesday evening I like to think of Orion as one of the Kansas City Royals (choose your favorite) about to hit a grand slam.

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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.

March 2015 Equinox and Solar Eclipse

   Friday March 20th is an equinox day. This means that for those in the northern hemisphere winter is ending and spring has ‘sprung’ (starts). For our counterparts south of the equator summer is ending and fall is beginning. From a geographical perspective we would describe the Sun as being over the Earth’s equator, and as this graphic shows there would be an equal amount of daylight and night on our planet as a result.
    At mid-day on the equator the sun is directly overhead and from that latitude you have no shadow, just a ‘blob-like’ shadow at your feet as this picture of my feet taken at mid-day in Quito Ecuador shows.

    Regardless of your hemispheric preference get outside and cast a shadow!

seasons-ani  Northern hemisphere spring officially (well at least astronomically) begins at 22:45 UT (4:45 pm CST) on the 20th when the Sun reaches the celestial coordinates of 0 hours and 0 degrees as it moves northward along the ecliptic crossing the celestial equator. At this location the Sun is within the constellation of Pisces the Fishes and not just entering Aries the Ram as the pseudoscience of astrology would have you believe.

    To learn more about the celestial coordinates click here to read a previous post about seasons and the equinox.

   The time of this equinox is about 13 hours after a new Moon phase and a solar eclipse. This picture shows the shadow of the Moon cast on the Earth during a solar eclipse as seen from the International Space Station.

   Click here to see the online world sunlight map used to make the day/night graphic at the top of the page.

sun-earth   Click here to go to the NASA Sun-Earth Days web site.

   Here is a short series of hourly pictures taken during the day on the September equinox on the equator in Quito Ecuador at Collegio Menor San Francisco de Quito, a private school that I visited and did the SunShIP project with (Sun Shadow Investigation Project).

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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.

Stretching the Sunlight

lion2lamb   The skies of March reflect the transition from winter to spring in the northern hemisphere, and is also the time when some say that “spring comes in like a lion and goes out lamb”. This has to do with the placement of the constellations Leo the Lion and Aries the Ram (not a lamb), as this graphic below is showing.
   This time change coincides with the season change and is seen in the sky with Leo rising in the east while Aries sets in the west. Between these two are the easily recognized stars belonging to Taurus the Bull, Orion the Hunter,and others that are associated with northern hemisphere winter night skies.
springforward   Time also shifts as we gradually transit seasons. The United States as well as other countries will make the shift from Local Standard Time to Daylight Saving Time on Sunday March 8th by setting clocks forward one hour. Hence we “spring forward” one hour.
   This adjustment was first proposed by an Englishman, William Willett, in his pamphlet Waste of Daylight, published in 1907. It took nearly ten years for the idea to catch on before it was passed into law by the United States Congress as the Standard Time Act in 1917. The entire country, U.S.A., was placed under Daylight Saving Time starting on March 30, 1918. This occurred during our involvement in World War I and the act was adopted in part to help the war effort by increasing the number of usable daylight hours and saving energy. At the close of the war, the act was repealed and was not reinstated on a permanent basis until the start of World War II.
   Over the years, the dates for the two time shifts has fluctuated but now due to the Energy Policy Act of 2005 Daylight Saving Time, in the U.S.A., begins on the first Sunday in March and ends with the return to Standard Time on the first Sunday in November.

   It is Saving time, not Savings Time. Savings are what you do with money in a bank.

   
   
   
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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.

Imbolog – 2015

   Watch That WoodChuck!
groundhog newspaper   On February 2, we watch for the groundhog to emerge for reasons that originate from ancient Celtic tradition. Groundhog Day was known as lmbolog, or sheep’s milk, a time for nurturing young sheep and planting spring crops. The belief arose that if lmbolog were to be sunny and clear, then winter’s effects would endure, foreshadowing a long winter. How­ever, if skies were overcast, then the warmer days of spring would arrive early. To farmers then and today, an early spring means early spring plant­ing and a subsequent early harvest. Often fires were lit to commemorate the event as fires were a sign of warmth and light, both of which increased as days lengthened.
not a meteorologist   German immigrant farmers are credited with bringing Groundhog Day with them to the United States as they settled in Pennsylvania. To them, February 2 was called Candlemas Day, because of the practice of lighting candles on this day in celebration of early planting. The Germans believed that the badger was able to predict the weather on the basis of whether or not its shadow appeared. If the badger, or groundhog, saw its shadow on Candlemas, it would be scared and return to its burrow for another six weeks to sleep through the long winter. However, if the skies were cloudy then no shadows would appear, and an early and warm spring would be expected. The importance of this day to German immigrants, and its impact on their farming gave rise to the couplet:
         A farmer would rather see his wife upon a bier,
         than that Candlemas Day should be sunny and clear.

puxs-phil-lied   Year after year, since 1898, crowds have gathered in Punxsutawney, Pennsylvania, on February 2 to wait for a certain groundhog to emerge from its burrow. Today the belief in this as a predictor of weather is not nearly as consequential as it appears despite all the hoopla created by the news media. Yet, there is some scientific rationale to this ritual, albeit not in the accuracy of the forecast. When the skies are clear, temperatures tend to be cold as the ground radiates heat absorbed during the day back into the atmosphere; and when skies are over­cast temperatures tend to moderate as clouds trap heat nearer the ground.
Midpoints
Groundhog-Standing2   To other cultures in the Northern Hemisphere Candlemas Day was celebrated as the midpoint, or cross­ quarter day, between the winter solstice and the spring equinox. Cross-quarter days occur midway between the astronomical events that mark the beginning of each of the four seasons, the solstices and the equinoxes. The second cross-quarter day of the year, as it is calculated mathematically, occurs on May 6, although it is often associated with May Day, on May 1. The third cross­ quarter day of the year is August 7, the only one of the four without a significant event associated with it. Mid-autumn, the fourth cross-quarter day, occurs on the last day of October, Hallowmas Eve, or as we now know it, Halloween.
   Interestingly this system of equinox, solstice, and cross-quarter days has led to some confusion as to when the seasonal midpoints and endpoints occur. For example, June 21 is the official date for the start of summer in the Northern Hemisphere, but it is sometimes referred to as midsummer’s day. This would suggest that summer actually begins on May Day and ends in early August. In a similar manner, December 21, the start of winter for the Northern Hemisphere, is some­times referred to as midwinter’s day. This would imply winter actually begins at the end of October, and concludes (assuming no shadow is seen) on Groundhog Day.
groundhog   So will we have a long winter, or will it be short, and our spring be an early spring? No one can predict this, at least not based on seeing one’s shadow. However, come this February 2, rest assured that crowds will once again gather to watch Punxsutawney Phil emerge from his hole.
   Adapted from “Watch that Woodchuck” Scope on the Skies. Science Scope Magazine. February 1993.

   
   
   
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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.

Luna Has Aquarius’s Back

Click on graphic to see it full size.

Click on graphic to see it full size.

   This evening, Sunday 10 November, the first quarter Moon is high above the southern horizon at sunset local time. Since yesterday the Moon has been waxing its way through the water part of the northern hemisphere celestial sphere. Here ‘swim’ the northern fishes, and from the mythologies a sea-goat, and some dude dumping a bucket of water into the mouth of the southern fish. As this graphic set for 7:30 pm CST shows, the Moon is in a region of not very bright stars – the exception being the 1st magnitude star Fomalhaut in the ‘Southern Fish’.
s toe pan   However turning toward the eastern horizon will bring into view the beginning of the stars and constellations making up the ‘winter hexagon’ (northern hemisphere) group of bright winter season stars. These include the open star clusters the Pleiades and the Hyades. The star Algol, a variable star in the constellation Perseus the Hero is now also in prime viewing for timing and graphing a light curve showing how this star varies in brightness. More on this in a future post.
   
   
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.