Mercury at Western Elongation

19jan-mercury-east-elongation
   On Tuesday September 12th Mercury, the innermost planet, will reach its orbital position known as greatest western elongation at 17.9o. At that moment Mercury, the Sun, and the Earth, would be arranged in something close to approximating a right angle as this graphic shows. Even though it sounds confusing at western elongation for either Mercury or Venus the inner planet will be to the right of the Sun as we view them, meaning that at western elongation an inner planet rises in the east before the Sun rises. And at eastern elongation with the inner planet on the left side of the Sun the inner planet follows the Sun across the sky setting after the Sun sets.
orbital-positions
   From our perspective the orbits of Mercury and Venus appear to move from one side of the Sun to the other – out to the left (east) from the Sun to eastern elongation, then reverse and move westward (inferior conjunction) between the Earth and the Sun to western elongation. From there the inner planet moves eastward going behind the Sun (superior conjunction) and eventually reappearing on the eastern side of the Sun for an eastern elongation. Repeat over and over – do not stop!

   Mercury is visible in the morning skies before sunrise along with Mars, Venus, and the star Regulus as this graphic shows.

   
   
   
   
   

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.

Leo and the Planets

   Friday morning September 25th the planet Mars will be within 1o from the star Regulus in Leo the Lion. Both shine with nearly the same apparent magnitude, Regulus (1.34) and Mars (1.78), making them look sort of like a binary system composed of a reddish star and a blue-white star. Interestingly Regulus is a multiple star system composed of at least 4 stars, with Regulus the brightest.
mars-regulus-venus-cropped   Here is a picture from that morning.
   You may also notice that there are three planets now visible in the hours before sunrise. Things will only get better with morning planet viewing as this year comes to an end. Saturn will join the group and then by the end of January Mercury will become the fifth morning planet visible. This animated graphic is set for 7:15 am local time on the 15th of each month.
Pay attention to the graphic for December. It is possible that Comet Catalina (C/2013 US10) may still be visible – that is assuming that it has brightened as predictions have suggested.

Stay tuned!

 

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-Jupiter-Regulus Conjunction

   Begining with Thursday July 16th and continuing for a few days there will be a nice triple conjunction involving Venus, Jupiter, and the star Regulus in Leo the Lion. In addition the waxing crescent Moon passes across this part of the sky adding to the viewing enjoyment. So between the 16th and the the 20th, at least, keep an eye on the western horizon sometime after sunset local time for this latest dance of the planets with the Moon.

July 16-20   This series of conjunctions will be close enough so that Venus, Jupiter, Regulus, and the Moon will all fit within the field of view of a pair of binoculars. This animated graphic shows a simulated view as seen through a pair of 7×50 binoculars and is set for July 16th to the 20th.

   I’ve been following the movements of Venus, Jupiter, the Moon, and Regulus since June 19th, and other than the evenings when the skies were cloudy, and with one location difference, I have been able to document this event with pictures. Click here to see the pictures.

   
   
   
   

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.

Leo Paws the Moon!

   Monday evening the waxing gibbous Moon will be within 3-4o from the heart of Leo the Lion, the star Regulus. Both fit comfortably within the field of view of a pair of binoculars.
   Regulus, viewed as a bright star with an apparent magnitude of 1.3, is located at a distance of 78-79 light years from the Earth. Regulus is actually a multiple star system consisting of 2 pair of stars. Regulus is paired with a smaller companion star, possibly a white dwarf star.
   Read more about the star Regulus at the EarthSky web site.

   
   
   

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.

The Weekend Moon

moon-bino

   This weekend the waxing Moon will pass by the open star cluster, M-44, the outer planet Jupiter, and the heart of Leo the Lion, the star Regulus. M-44, or the Beehive Cluster, is an open star cluster comprised of about 1000 stars, and located at a distance of around 600 light years from the Earth. On the evening of the 25th the three will all fit, more or less, within the field of view of 7×50 binoculars – as this graphic shows.
   The slide show below shows the sky at 10 pm CDT for the next three evenings, starting with Saturday the 25th.
   
   

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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.

Double or Triple Dating?

Click on graphic to see it full size.

Click on graphic to see it full size.

   Tuesday evening after local time for sunset there will be an opportunity to see several interesting pairs of celestial objects divided among three planets, our Moon, and several asteroids as this graphic shows. Jupiter is the single this evening, over the southwestern horizon near the twin stars of Pollux and Castor. Higher above the southern horizon is the constellation Leo the Lion with its distinctive backward question mark star pattern. At the bottom of the question mark is one of the celestial pairs, the star Regulus and the nearby asteroid 2 Pallas. Continuing eastward is the Dwarf Planet Ceres paired up with one of the larger asteroids, Vesta. Mars and the blue-white star Spica form the base of a triangle with the two asteroids as the point. Looking further eastward for the third celestial pair, and outshining everything else is the very near full Moon and a few degrees away the planet Saturn.

Click on graphic to see it full size.

Click on graphic to see it full size.

   As this graphic shows the asteroid 2 Pallas is close enough to the star Regulus in Leo so that both fit within the field of view of binoculars. Regulus shines at magnitude 1.4 while about 2 degrees away is the 8th magnitude asteroid Pallas.

   
   
   
   
   
   
   
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.

A Cat and His Ball

Click on graphic to see it enlarged.

Click on graphic to see it enlarged.

   This evening the waxing gibbous Moon rises within about 7 degrees from the star Regulus in Leo the Lion. This graphic is set for 9 pm CDT (2 UT 14 March) and shows a closeup view of the area around Leo including the star Omicron Leonis, a star with a apparent magnitude of 3.5 about 1 degree from the left edge of the Moon.

Click on graphic to see it enlarged.

Click on graphic to see it enlarged.

   This time of the year is interesting from a ‘viewing constellations’ perspective. Over the south to western horizon are the stars of northern hemisphere winter, while the stars of the next season are over the east to southern horizon. Part of this includes the large asterism called ‘The Diamond of Virgo’. This is made up of 4 stars, each one borrowed from a different constellation. Cor CaroliCanes Venatici the Hunting Dogs; DenebolaLeo the Lion; ArcturusBootes the Hunter; and just below the horizon is Spica in Virgo the Harvest Maiden.
This graphic is also set for 9 pm CDT on 13 March and is a northern hemisphere view of the sky facing toward the southern horizon.

   
   
   
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.