Sun Not in Taurus

April 19th

April 20th

  According to the pseudoscience of astrology the Sun enters the constellation of Taurus the Bull on Monday April 20th at 4 am CDT (10 UT). When in fact the actual position of the Sun on the 20th is still within the boundary of the constellation of Aries the Ram, as this graphic shows. Actually the Sun had just entered Aries on April 19th.

   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 Aries

April 19th

April 19th

   Sunday April 19th at 4 am CDT, (10 UT), the Sun in its apparent eastward motion along the ecliptic, moves out of the constellation Pisces the Fishes and into the constellation of Aries the Ram. 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.
   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.

April 17 Moon at Descending Node

apr17-descending-node   Friday April 17th at 13:06 UT, (8:13 am CDT), our Moon will be crossing the plane of the ecliptic moving south. This is known as the descending node, one of two intersections the Moon’s orbital path (dark green line) has with the ecliptic.
   The Moon reaches new phase more than 24 hours after it makes the node crossing. Had this been closer to the time of the node crossing we could have had an lunar eclipse. This was the situation last month for the total lunar eclipse.

   
   
   
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.

April Perigee Moon

apr17-perigee   The Moon reaches perigee, (minimum distance from Earth), this month on Friday April 18th at 03:47 UT (10:37 pm CST Thursday April 17th). At that time the Moon will more or less be at a distance of 28.30 Earth diameters (361,023 km or 224,330 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)

The Moon reaches new Moon phase at 18:57 UT on Friday April 18th. The Moon will rise and set with the Sun but the Moon will not be visible today.

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)

   
   
   
   
   
   
   

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.

Venus and the Sisters-Pictures

   It never fails! Whenever I start making plans for taking out the telescope, or for taking some night pictures, the weather goes in the opposite direction. So after a couple of nights of cloudy skies last night the skies were clear (after some cirrus clouds threatened to eclipse the sky early in the afternoon), so I set up my camera for some pictures of Venus near the open star cluster, the Pleiades. I am using a new camera control software called Helicon Remote on my Kindle HDX tablet. I also use their PC version on my laptop. Both programs allow me to see a live view of the scene, and to adjust my camera settings, including focus, remotely. My camera is not WiFi equipped so I connect with a USB cable.
   Here are two of my attempts. The first taken at 7:45 pm CDT while the twilight sky was not yet dark. The picture was taken with the following settings: f/5.6; 1 sec.; ISO-6400; 135mm. This one taken at 7:55 pm CDT using these settings: f/5.6; 1 sec.; ISO-3200; 190mm.

   Weather forecast this evening? Cloudy and rain – of course!

   
   
   
   

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.

Yuri’s Night

yuri   April 12th 1961 Cosmonaut Yuri Gagarin became the first human to leave the surface of the Earth and orbit our planet. Coincidentally 20 years later, on the same date in 1981 the United States launched its first space shuttle, the Columbia. However April 12th is a date for celebrating the accomplishments of the Russian space program and the cosmonaut who became the first to orbit the Earth. So, on April 12th people around the world will take part in local events in what is known as Yuri’s Night. Use the link to the Yuri’s Night web site to learn more about this event and to see if there is a Yuri’s Night event in your area.

yuri   A few years ago I had an opportunity to work with a group of musicians (Dark Matter) in producing a series of videos about the solar system and our home planet that were then projected as full-dome videos on a Planetarium dome ceiling. Accompanying the videos were two musicians playing their respective instruments (Flute and Clarinet) along with electronic notes, live sampling of their music, and sounds of the interior of a spacecraft. Below is a version of that performance that was entered into a worldwide contest – placed in the top five by the way.

   
   
   
   

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.