Star Calendar – May, 2016

Star Calendar

May, 2016

Star Calendar Planets:

Moon is Full three, or sometimes four, times in a season but the names that various cultures have assigned to characterize the circumstances around various full moons of the year generally number 12 – leaving the occasional unnamed one. Similarly the Hebrew luni-solar calendar has 12 months – but needs to insert an inter-calary month about every three years to maintain its relationship to the solar year. In each case the adjustment occurs 7 times in 19 years – the extra full moon is called Blue and the extra Hebrew month is called second Adar. This month’s full Moon coincides with the opposition of Mars – and the latter will shine in the very spot towards which falls the shadow of the Earth – so on the night of the 21-22nd one can easily see just how far the moon is from being eclipsed.

Mercury promises to be visible in broad daylight on the 9th. Inferior conjunction will cut right across the face of the Sun, beginning somewhat after sunrise, midway around 11 and leaving in mid-afternoon. One can observe this with a camera obscura arrangement that projects and enlarges the disk of the sun onto a screen. I might cover a south or SE-facing window and allow a pinhole of light through a piece of aluminum foil to cast onto a sheet of white cardboard. Such a transit of Mercury last occurred ten years ago – but these are far less rare than transits of Venus – which I will never see again.

Venus is lost in morning limelight as she heads backstage for some future showing in evening attire.

Sun is midway from equinox to solstice on the 1st. Astronomically this marks the beginning of Summer, the solstice being regarded as mid-summer. The days are now getting longer much more slowly – by about one minute a day as the month opens and only 30 seconds a day as the month ends.

Mars makes a large retrograde stroke and rises dramatically earlier over the course of this and next month. He breaks the horizon at about 9 PM on the 1st and already at 6:18 by the 31st.  This opposition is the nearest for Mars since the superlative one of ten years ago. But, due to Mar’s high degree of ellipticity, he will continue to draw nearer for another week after opposition, then being twice as near to us as is the Sun (.5AU).

Jupiter finally diminishes perceptibly from its late brilliance but still dominates the evening sky in the south. Mars will match magnitude during its opposition- but rises later and culminates much lower – achieving only the altitude of the Sun at mid-winter.

Saturn is also in a retrograde loop, one much smaller than Mars’, and rises just under an hour later. Saturn is then seen to be about as bright as Arcturus – but shining with a steady light compared to the latter’s yellow-green scintillation. Saturn will reach opposition on June 3rd.

Star Calendar Days:

  1      Sunrise/sunset in Spring Valley at 5:53/19:54 (14h1m daylight)

          First day of cross-quarter-wise summer, Beltane

  6      New Moon 15 hours after perigee, again large spring tides

  8      Moon to right of Betelgeuse and above Aldebaran, WNW around 9:PM

  9      Mercury crosses face of Sun (transit) begin 7:12-max 11:-ending 2:40

          Jupiter stationary to direct motion, ends it’s loop for this year

13      Moon next to Regulus, SW as dark falls

14      Moon next to Jupiter, SSW as dark falls

18      Moon beside Spica, SE as dark falls

21      Full Blue Moon at 17:14 (This season has 4 Full Moons, the 3rd is “Blue”

          Mars rises (in the exact direction of Earth’s shadow) beside the Moon, ESE 8:30PM

          Mercury stationary to direct (leftwards motion against stars)

22      Mars in opposition 7:AM, 14 hours after Full Moon

          Moon rises to left of Saturn, SE at 10:PM

30      Mars is nearest Earth, half as distant as is the Sun

31      Sunrise/sunset in Spring Valley at 5:26/20:22 (14h56m daylight)

Star Calendar – April 2016

Star Calendar

April 2016

Star Calendar Planets:

Moon is very dynamic and has several motions of similar mode. A Frenchman sewed photographs of sequential Full Moons together into an animated GIF that shows very nicely the net effect of the various librations – the nodding and swaying face and changes in proximity in a kind of slow stroboscopic form. The next-to nearest perigee for this year coincides pretty closely to New Moon this month – the waters will respond. Of note; the center of mass of the Moon is well displaced from its geometrical center. This lopsidedness is probably why we see only one side of the Moon – its center of mass prefers to be toward the earth.

Mercury is an evening star all this month. With a good view to just North of West one might find him to the right of a thin Moon around 8:15 PM on the 8th. Thereafter he will be higher until the 18th, then seen below the Pleiades as late as around 9PM.

Venus is now difficult to view in the morning. With a very good East horizon try to look to the left of the Moon on the 4th at 6:10 AM – Venus will next appear some evening in latter July.

Sun is not a point of light – rather a disk of ½ degree or 1/720th the circumference of the sky. Due only to this the Sun is visible above the horizon to slightly more than ½ of the planet at a time. In addition, the medium of air, increasing in density from empty space, bends the visibility of the Sun a further half-degree or so beyond the geometric-tangent horizon, trebling the effect. At any moment, roughly 50.4% of the Earth is in daylight. This has to do with why day and night are not of equal length on the equinox.

Mars approaches headlong this month and brightens dramatically. He does so near Antares (similar color but much dimmer) and Saturn, to his left. Recall that Mars and Saturn were of equal brilliance in mid-February – now look at the difference! Mars’ opposition is coming May 22nd. They are visible, low and southerly, between about 11PM and 5:30AM.

Jupiter appears much the same as last month, repeating a prominent pairing with the Moon on the night of the 17th.

Saturn makes a nice contrast to Mars and will be in its opposition on June 3rd, only 12 days after Mars’.

Star Calendar Days:

  1      Sunrise/sunset in Spring Valley at 6:39/19:22 EDT (12h43m daylight)

  6      Moon and Venus rise together – only with a perfect view east, at 5-5:10AM

  7      New Moon and very-near perigee only 6 ½ hours apart – spring tides

  8      Moon and Mercury set together – only with a perfect view west, at 8-8:30PM

10      Aldebaran emerges from occultation by Moon as they set; West, 8-11PM

12      Moon passes Alhena (foot of Gemini) WSW in evening

14      Moon makes a line with Pollux and Castor (heads of Gemini) SW in evening

16-17 Moon passes Regulus

17      Mars stationary to retrograde, brightening most rapidly now

17-18 Moon and Jupiter make a bright couple all night (like last month)

18      Mercury at largest angle from evening Sun for this appearance

20      Mars and Saturn nearest (no conjunction), visible SW11:30PM to SSW5:30AM

21      Moon setting with Spica WSW at 5:30AM

21-22 Full Sprouting Moon at 1:24 AM

23      Passover begins, the 15th of Nissan

24      Moon, Mars, Saturn & Antares rising together SE at 11:30PM

26      Mars, the brighter, nearest to Antares – of similar color; culminate S at 3:AM

29      Mercury stationary, to retrograde

30      Sunrise/sunset in Spring Valley at 5:55/19:53 (13h58m daylight)

 

1/3 of 2016 has passed; also midway from Spring equinox to summer solstice

 

 

Star Calendar – January 2016

Star Calendar

January 2016

Star Calendar Planets:

Moon rises on the autumnal equinox point and beneath Jupiter as the New Year opens. On the 7th it accompanies Venus and Saturn in morning twilight in the ESE and then begins another week or so of moonless dark nights. On the evening of the 19th watch the Moon, high in the south, approach and then blot out Aldebaran – that expected to occur at 9:43PM.

Mercury stands (against the stars) on both sides of the Sun this month. He is stationary on the 5th, on the evening side of the Sun, in Capricorn; crosses the nearside of the Sun on the 14th, and stands again on the morning side of the Sun on the 25th. This appearance is rather poor – but the dates give a sense of how quickly Mercury can change position.

Venus continues to be the dominant “star of the east”. On Three King’s Day morning will occur a lovely morning group of crescent Moon, Venus and approaching Saturn; and the subsequent days too – until on the 10th she sinks below Saturn and begins in earnest to fall into to the morning glow.

Sun is nearest us for the year at this time. The relationship of the timing of the proximity cycle of the Sun (apsides) to the seasons is a strong component of the cycle of glaciation; is one that changes very slowly too. All of modern humanity’s historical records fall within the current warm cycle. Apsides proceed to the same conditions in about 111,000 years while the seasons are retrograde in 25,770 years. Other long cycles also abound.

Mars is culminating (south and highest) between 6 and 6:30 AM these days. He abandons the virgin on the 17th and recovers his balance in the scales. Mars is at 1st magnitude, slightly brighter than Spica to his right. He approaches 3rd magnitude (much dimmer) Zuben Elgenubi this month and will arrive, escorted by the Moon, on Feb. 1st.

Jupiter begins his loop this month, wandering back under the belly of Leo for an opposition in early March.

Saturn is now a definite morning presence, shining as brightly as Arcturus in the morning sky. As the year opens Saturn will be only half as high as Venus at 6:30 AM, but will ascend each morning as Venus slowly falls. The pair swap ascendency on the 9th and by the 31st Saturn will be prominent in the SSE between Antares and Sabik – though one might have to look a little earlier due to earlier sunrise!

Quadrantids are from the upper part of Bootes and their radiant is circumpolar. They may peak early this year so spending the night of 3rd-4th on a cot with feet facing north may reward.

Star Calendar Days:

1      Sunrise/sunset in Spring Valley at 7:21/16:38 (9h17m daylight)

2      Sun is nearest for the year (perihelion), at .9833 of average distance

3      Martian solstice, summer for northern hemisphere

          Moon above Mars and Spica, SSE at 6-6:30AM

4      Quadrantid meteors early AM, from high East –

          – while looking, find Comet Catalina above Arcturus (with binoculars?)

5      Latest sunrise for the year, at 7:22 in Spring Valley

          Mercury stationary to retrograde

6      Moon above Venus and Saturn in morning twilight

7      Moon below Venus and Saturn, (red Antares to the right)

          Julian December 25, Orthodox Christmas

8      Jupiter is stationary, begins retrograde loop

9      Venus and Saturn very near, morning twilight in east

14      Julian/Roman New Year, begins 2769 AUC

          Mercury at inferior conjunction, crosses nearside of Sun

19      Moon occults Aldebaran, SSW at about 9:43PM

23      Full Wolf Moon at 8:46PM

25      Mercury stationary to direct (normal) motion

          Moon rises beside Regulus, east at 8:PM

28      Moon rises below Jupiter, east at 10:PM

30      Moon above Spica, SSW at 6:AM

31      Sunrise/sunset in Spring Valley at 7:08/17:12 (10h4m daylight)