March Moon at Apogee

 Our Moon reaches apogee, (greatest distance from Earth), on Saturday March 18th. At that time the Moon will more or less be at a distance of 31.72 Earth diameters (404,640 km or 251,432 miles) from the Earth.
   Does our Moon actually go around the Earth as this graphic shows? From our perspective on the Earth the Moon appears to circle around the Earth. However, in reality, the Moon orbits the Sun together with the Earth*

*Click here to read my 2006 Scope on the Sky column “The Real Shape of the Moon’s Orbit”. (PDF)

Read this very informative article about the Earth-Moon system and their orbital motions, written by Joe Hanson. “Do We Orbit the Moon?”

   On the morning of the apogee Moon the 20-day old waning gibbous Moon rises a couple of hours before the Sun and is visible over the southern horizon.

   
   
   

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

Sun Not In Virgo

   
According to the pseudoscience of astrology the Sun enters the constellation of Virgo the Maiden on Monday August 22nd. When in fact the actual position of the Sun today is toward the west and still within the boundaries of the constellation of Leo the Lion.

   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 go to bobs-spaces.

Follow the Moon

   Over the next several days the Moon, as it waxes toward full phase, will follow the ecliptic as it passes by some of its solar system colleagues. Starting on the 15th, a few degrees east from the blue-white star Spica in Virgo the Harvest Maiden, the waxing gibbous Moon will then pass a few degrees from Mars on the 16th and 17th. Then on the 18th the nearly full Moon will be about 3o from Saturn, and that night ending this month’s lunar sweep along the ecliptic and bright planets.
   This animated graphic shows an 'atlas' view of the area along the ecliptic and the the Moon's daily path from June 15th to the 20th. The celestial equator is the curved red line and the ecliptic is the green line.
   There are two distinct motions, and one subtle motion shown in this animation.

    -Planets are in motion with Saturn and Mars on the move with Mars moving toward the west as it retrogrades. On a day to day basis the subtle shift in the position of Saturn and Mars each day is relatively small. Saturn moves 0.033o each day (360o/10,755 Earth days), and Mars each day moves 0.52o (360o/687 Earth days) .
    -The Moon orbits from west to east so each day at the same time the Moon is further to the east, or rises (sets) later.
    -The daily shift in the sky from east to west due to the Earth’s revolution around the Sun. The sky shifts about 1 degree each day or celestial objects, like stars, rise (and set) about 4 minutes earlier each day.

   The graphics below are set for 10 pm CDT on the dates indicated.

This slideshow requires JavaScript.

   
   
   

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

3 Pairs or A Tale of Two Tails

   For the past month or so Comet Catalina (C/2013 US 10) has been moving in a northeast direction across my morning skies. It has hovered at around 6th or 7th magnitude making it somewhat visible in binoculars and obviously visible with telescopes. Sadly with my meager photo equipment this comet has so far eluded my efforts. There are some spectacular pictures showing a comet with a greenish tinge and two tails. However that is not the point of this posting.
Bootes, Arcturus and the comet   Over the next several mornings the comet will pass by the reddish star Arcturus in the constellation Bootes the Herdsman. To many the star pattern for this constellation resembles a kite shape and Arcturus is at the bottom of the kite where the kite tail is attached. The animated graphic shows the comet in motion for December 31st and January 1st.
   The morning sky, in addition to the comet – Arcturus pair, also contains two other pairs, or conjunctions. Jupiter has the Moon for a one-day partner and further east toward the horizon is Mars and the bluish star Spica in Virgo.

   
   
   
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.

It Is Okay To Point

clicl on picture to see it larger   During the lunar eclipse the other evening (on my side of the world) I had, for a time, the company of my daughter, granddaughter, wife, and our dog Tyler. As my daughter pointed toward the Moon and helping our granddaughter aim her binoculars I had this cosmic thought. Am I the only one wondering “if the Moon is there where is the Sun?” Obviously more or less 180o away from where the Moon is. After all this is a full Moon. So by putting the Moon behind you point toward the ground at an angle that is the same as the angle the Moon is above the horizon. That is where the Sun is at that moment.
camera-points    A look at how I had my camera setup sort of conveyed that idea as well.
   The Moon is within the constellation of Pisces near the vernal equinox, the crossing between the ecliptic and celestial equator. This means the Sun, if opposite from the Moon, would be at a similar crossing but the opposite season in the constellation of Virgo the Harvest Maiden – the autumnal equinox.

   Some pictures of the lunar eclipse around the center of my universe.

   
   
   
   

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 Not in Virgo

   
According to the pseudoscience of astrology the Sun enters the constellation of Virgo the Maiden on Sunday August 23rd at 11 UT (6 am CDT). When in fact the actual position of the Sun today is still within the boundaries of the constellation of Leo the Lion.

   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.

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.