AM-PM Astronomy

Click on graphic to see it full size.

Click on graphic to see it full size.

   Tuesday morning November 4th the innermost planet, Mercury, will be rising above the eastern horizon about 4-5o away from the bluish-white star Spica in the constellation of Virgo the Harvest Maiden. For an interesting comparison between two stars based on temperature look up to the left from Spica and Mercury for a reddish star, Arcturus, in the constellation of Bootes the Herdsman.
   Arcturus is red giant star approximately 37 light years from the Sun and at nearly 35 times the size of the Sun has a surface temperature of 3,833oC. Spica is a blue-white star approximately 2600 light years from the Sun and at nearly 10 times the size of the Sun has a surface temperature of 23,096oC. Both stars are also one of the two stars making up their respective binary system.

4nov-pm   Later that same day the nearly full Moon will be rising a few degrees away from Uranus, the next to outermost of the 8 planets. Uranus is right at the unaided eye limit and is easier seen with some sort of optical aid. In reality since the nearly full Moon is nearby moonlight would brighten the surrounding sky more then enough to make most anything nearby ‘invisible’.
   Uranus is about 14 times larger than our Moon so what would Uranus look like if it was where our Moon is?

   
   
   
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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.

Saturn, Mars, and the Moon

Click on graphic to see it full size.

Click on graphic to see it full size.

   Sunday evening August 31st the 6.5 day young waxing crescent Moon will be close to the planets Mars and Saturn. All three objects of this triple conjunction will easily fit within the field of view of binoculars. Closest will be at 19 UT (2 pm CDT) but there will be parts of the world that may be able to see the Moon occult (pass in front of) Saturn.

   
   
   
[centup]
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.

Jupiter Rising with the Moon

March 23 - 7 p.m. CDT

March 23 – 7 p.m. CDT

   This evening, 23 March, the waxing gibbous Moon rises around 4 pm local time and by 9 pm local time the sky has darkened enough to make the bright Moon really hard to miss. (Now if I had said this to my grand daughter she would probably reply in her 6 year old voice, “Seriously…, grandpa?”).
   Seriously, the bright star that rises after the Moon and, as the Earth rotates, follows the Moon across the sky toward the west is the heart of Leo the Lion, the star Regulus. The animated graphic below shows the stars of Leo and the waxing gibbous Moon at 9 pm local time. All of the stars forming the asterism shape for Leo, the backward question mark and triangle, are labeled, and the stars are connected with lines to show the constellation pattern.
dogs   In the third image of the 3-picture sequence the triangle forming the lion’s tail is not drawn but the star Denebola, making the triangle’s point, is used as one of the four corners for the ‘Diamond of Virgo’ asterism. The opposite corner of the ‘diamond’ is the reddish star Arcturus belonging to the constellation Bootes the Herdsman. The upper star of the diamond is Cor Caroli, on of the stars belonging to the constellation Canes Venatici, the ‘Hunting Dogs’ used by Bootes to drive off a bear according to one sky story. And off to the left are the seven stars making the asterism the Big Dipper, part of Ursa Major ‘the Great Bear’.

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

Stairway to the Horizon

7:00 a.m. CST - 8 December

7:00 a.m. CST – 8 December

   The waning Moon this morning was poised to start the first of several conjunctions with planets and a star over the next few mornings. Go out around sunrise your local time each mornig and look toward the southeast horizon for the Moon as it sort of stair-steps its way toward the horizon.
   The Moon is also passing through a part of the sky housing a menagerie of characters including a Harvest Maiden, a Crow, a Wine Goblet, an Equal Arm Balance, and of course a many headed snake! Click here to see a graphic illustrating what I am writing about.

Sunrise - 9 December

Sunrise – 9 December

   The Moon will be near the blue-white star Spica in Virgo the Harvest Maiden on Sunday morning 9 December.
Sunrise - 10 December

Sunrise – 10 December

   The Moon will be near the planet Saturn on Monday morning 10 December.
Sunrise 11 December

Sunrise 11 December

   The Moon will be near Venus and Mercury on Tuesday morning 11 December.

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

Follow the Arc

The ‘Evening Arc’

   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 north to find the 7 stars making up the Big Dipper, look for the curved handle and follow the arc or curve 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. However you can start this observation at sunset by looking northwest for the Big Dipper and then toward the southwest for the star Arcturus. Do this early enough as Arcturus sets about an hour after sunset and in the next couple of weeks Arcturus will become too close to the Sun and will not be visible again until later during the winter as a morning visible star.

The ‘Morning arc’

   And you could continue this observation the following morning as this part of the sky rises before the Sun and you trace out the arc passing through Arcturus and ending at Spica. As the ‘Morning Arc’ graphic shows the planet Venus is close to Spica.
   Keep an eye on this part of the sky as later this month the planets Saturn and Mercury start becoming visible before sunrise. On the 26th Venus will be very close to Saturn. As the graphic shows the two planets will be close enough for both to fit within the field of view of binoculars.

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

Follow the Arc

Follow the Arc

No I’m not Noah and this is not the “Ark”!
Last night I had my first meeting with my Tu/Th evening class and so we went out around 8:30 for a look at the Moon, Mars, Saturn, and other celestial objects bright enough to be seen in the light polluted skies on campus.

So once I pointed out the trio of planets and star, plus the crescent Moon I directed their eyes toward the star Arcturus and then over to the handle of the big Dipper at which point I said those famous words: “Follow the arc to Arcturus and then speed to Spica“. This got their attention so I showed how them to find the North Star and about that time the ISS flew past our location going from north to north east giving us a couple of minutes of viewing.

As the graphic shows the waxing crescent Moon is still near the trio and the arc is still follow-able!