Sun Not in Pisces

The view from Earth - 18 February.

The view from Earth – 18 February.

  According to the pseudoscience of astrology the Sun enters the constellation of Pisces the Fishes on Saturday February 18th. In fact the actual position of the Sun is still within the boundary of the constellation of Aquarius the Water Bearer, as this graphic shows. The Sun had just entered Aquarius 2 days ago.

   Read a little more about how astrology has the Sun incorrectly placed in a previous blog, and in another blog discussing the effects of precession.
   
   
   
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.

Sun Enters Aquarius – 2017

feb-view from earth   Thursday February 16th the Sun in its apparent eastward motion along the ecliptic, moves out of the constellation Capricornus the Sea Goat and into the constellation of Aquarius the Water Bearer. This is the true or actual position of the Sun as opposed to the pseudoscience of astrology which usually has the astrological Sun one constellation ahead or east from the Astronomical Sun’s position, which will be Saturday February 18th when the sun is not in Pisces according to astrology.

   
   
   
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.

Sun Enters Capricorn and Aquarius

ww   Thursday January 19th at 14 UT the Sun in its apparent eastward motion along the ecliptic enters the boundaries of the constellation Capricorn the Sea Goat. This is the true or actual position of the Sun. However 7 hours later, at 21 UT, according to the pseudoscience of astrology, the Sun,will enter the constellation of Aquarius the Water Bearer.

   
   
   

Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to return to bobs-spaces.

Jupiter at Quadrature ——— Venus at Elongation

   Thursday January 12th the gas giant planet Jupiter reaches the point along its orbit around the Sun where Jupiter would be described as being at western quadrature. It is at a 90o angle relative to the Earth and the Sun.
   Also on this day the inner planet Venus reaches a point in its orbit known as eastern elongation. This puts Venus at somewhere around a 90o angle relative to the Earth and the Sun when viewed looking down from above the solar system but Venus is on the other side of the Sun from where Uranus is currently located.
   In terms of elongation Venus is 47.2o to the east of the Sun. In terms of viewing angle you are the point of a triangle with Venus at the left base corner and the Sun at the right base corner. The angle between the Sun and Venus is the elongation angle, and at 47.2o Venus sets around 3 hours after sunset as its seting motion or speed is (15o per hour based on Earth rotation rate.
   Where is Jupiter currently? Jupiter rises around midnight local time and is located high above the southern horizon at sunrise local time near the blue-white star Spica in Virgo the Harvest Maiden.
   And Venus? Can’t miss this planet as it is the brighest stellar object over the western horizon at sunset.
   
   
   

Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to return to bobs-spaces.

Pluto Ducks Behind the Sun

7jan
   Saturday January 7th the Dwarf Planet Pluto reaches a point in its orbit where it is on the opposite side of the Sun as viewed from Earth. This is known as solar conjunction.

   
   
   

Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to return to bobs-spaces.

Earth at Perihelion 2017

Earth at Perihelion   Feel the Heat?
   Wednesday January 4th at 14 UT (8 am CST), as the Earth continues its annual trek around the Sun, the Earth reaches a point in its orbit that is called perihelion. Perihelion is the minimum distance that separates the Earth from the Sun, and we are the closest to the Sun for the year at this point in the orbit. So the Earth, this year, is 0.98330 AU (147,101,082 km; 91,404,374 miles) (compared with last year 2016: 0.98331 AU (147,099,586 km; 91,403,445 miles) from the Sun. Approximately one-half year or one-half revolution later, on July 3rd, the Earth is at aphelion and is 1.01668 AU(94,506,310 miles; 152,093,163 km), its maximum distance from the Sun for 2017. This difference in distances is due to the shape of the Earth’s orbit being elliptical rather than circular. However the Earth has a mildly elliptically shaped orbit that is closer to being slightly out-of-round than the incorrect, very elliptical orbit that is often shown – like the illustration used here.

sun2014-ani   In Astronomy the shape of a planet’s orbit is called eccentricity, with 0 being a circle and 1 a straight line. Any value between 0 and 1 represents an ellipse. The shape of the Earth’s orbit is so close to being circular that the apparent size of the Sun does not appear to change as this animated graphic shows. The difference between perihelion and aphelion is about 3%.

   Eccentricity for each planet is listed below for comparison.

Planet	   Eccentricity	
Mercury	   0.2056
Venus	   0.0068
Earth	   0.0167
Mars	   0.0934
Jupiter	   0.0484
Saturn	   0.0542
Uranus	   0.0472
Neptune	   0.0086
Pluto	   0.2488

   To read more about the Earth’s orbit and get some teaching ideas click here to download a PDF copy of my January 2011 Scope on the Skies column Solar Explorations.
   Here is a good classroom activity about the Earth’s orbit and its effect on the apparent size of the Sun: Why Does the Size of the Sun Appear to Change? A Year of the Sun.

   
   
   

Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to return to bobs-spaces.

Sun Not in Capricornus but it is the 2016 December Solstice

sag-cap-ani    According to the pseudoscience of astrology the Sun enters the constellation of Capricornus the Sea Goat on Wednesday December 21st at 10:44 UT (04:44 am CST, when in fact the actual position of the Sun is still within the boundaries of the constellation of Sagittarius the Archer.
    In reality the Sun will have reached the celestial coordinates of 23.5o degrees south declination; 18 hours right ascension. With regard to the Earth’s surface this places the Sun over the Tropic of Capricorn, which is at 23.5o south latitude. We also know that it is the Earth’s tilt on its axis that is the cause for seasons on Earth rather than the distance between the Earth and the Sun. And of course we know that this signals the start of northern hemisphere winter and the southern hemisphere summer seasons.
earth-in-gemini    And for those ‘insanely curious’ like me, while the Sun is at 23.5o South declination and ‘in’ Sagittarius the Earth is opposite at 23.5o North declination and at the feet of the Gemini Twins.

   The animated graphic below sets the stage, so to speak, to illustrate the Sun’s actual location with respect to the zodiac constellations in the background. This is as opposed to the location of the Sun according to the pseudoscience of Astrology. The scene is set for 12:15 CST, or mid-day when the Sun is at an azimuth of 180o, or south, and is mid-way between rising and setting. Starting with the Sun at mid-day the scene changes as first the daytime sky is turned off, followed by the horizon being turned off.
   This leaves a sky view like during a total solar eclipse except that the Sun is not blocked out by the new Moon. And like during that solar eclipse the zodiac constellations in the background become visible. Then the following are added starting first with Sagittarius, then Capricorn, and then the ecliptic and celestial equator are added to show the relationship between the two constellations and what makes them plus another 11 constellations the astronomical zodiac of 13 constellations. The animation ends with the addition of the constellation boundary lines and labels for the rest of the constellations in this setting.
It is the ecliptic, the apparent path of the Sun which, if it crosses the boundary of a constellation, makes that constellation one of the zodiac. And during December the Sun’s apparent path takes it across the constellation of Sagittarius rather than Capricorn.

   Read a little more about how astrology has the Sun incorrectly placed in a previous blog, and in another blog discussing the effects of precession.
   
   
   

Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to return to bobs-spaces.