Regulus and the "Standing Sun"

Unlike Spica, Antares and other bright stars of the zodiac, Alpha Leonis (or Regulus) is quite close to the ecliptic. Around 2,000 years ago, this may have enhanced the importance of Regulus. Since the sun, near the summer solstice, was headed right toward it, the star may have been a key indicator of solar speed at the time. How quickly, or slowly, did Regulus fade as sol approached? That would be a reflection of solar motion (actually Earth's). But was Regulus still visible at all then, i.e. near the longest day of the year 20 or so centuries ago ? 

Back then the point of the sun's greatest ascent was not in western Gemini, where it is currently, but farther east in Cancer i.e. one constellation closer to Regulus. Therefore Regulus was overtaken by the sun in July instead of in August as it is now. Since the star disappeared a month earlier, in order to be observed near enough to the time of Earth's aphelion (July 4) for ancients to discern the effect (slowing or "standing" sun) it would still have to be visible in June. 

To test whether Regulus could still be seen in June a couple of millennia ago, one would have to be able to see it in July recently. In both cases the star would be about a month away from its rendezvous with the sun. Lately I doubted Regulus was still observable in July. But I had forgotten my observations of half a century ago. An old diary dispels any doubt.

From my latitude, about 42 north, Regulus is still clearly visible, even conspicuous, on July 6. I had no trouble seeing it on that date in '73 (see above). Over two weeks later, on July 24, 1973, there was a conjunction of Venus and Regulus. The planet finally caught up to the star. The evening before then (July 23) I saw Venus but not Regulus. But the latter was still at least as high. I believe it can still be seen on that date by those with better eyesight (especially in the clearer skies and lower latitudes of the Near East). I saw it (near Venus again) eight years later, on July 23, 1981, albeit barely, and with optical assistance (60mm refractor). Those with good vision can probably see it at least to July 21.

When the solstice was in Cancer, the equivalent date of last viewing would've been June 21 or so. To the ancients, Regulus would've remained visible to the time of the summer solstice. That was just two weeks from Earth's aphelion passage, when Earth moved most slowly in its orbit and hence sol moved most slowly along the ecliptic. In fact sol was already moving relatively slowly at least a month prior to that. The result was that Regulus appeared to "linger" for a surprisingly long time in June (just as it does, to a theoretically even greater degree, now inasmuch as its last appearances are even closer to the time of aphelion). Unable to overtake Regulus for an inordinate period, it seemed that the sun had slowed or even halted.

"Standing Sun"

This is one of the "Planets and Stars" articles by the late Prof. Charles H. Smiley. From about 1970 to his death in 1977, Smiley's  articles appeared monthly in The Hartford Courant. I collected several and still have them. I'm revisiting this one as it seems relevant at this time of year (actually a bit earlier).
Smiley's newspaper column was for laymen and therefore he could not use technical jargon. Note the article doesn't mention the reason for the apparent slow motion of the sun against the stellar background. At this time of year, or more precisely around July 4, Earth is at aphelion, the point of its orbit farthest from the sun. Like all planets, Earth moves most slowly when at aphelion. Since the sun's movement against the stellar background is a direct reflection of Earth's orbital speed, in July the sun also moves relatively slowly. It covers less distance along the ecliptic, amidst zodiac constellations such as Gemini, than at other times of the year.
 Of course, the stellar background can't be observed when the sun is above the horizon. But soon after it set, the ancients inferred the sun had slowed, or even stopped, since it took longer for certain stars to be overtaken and become invisible (until reemerging in the morning sky, as the sun, still moving eastward, left them behind). Around 2,000 years ago, when the point of the sun's highest ascent in the sky was in Cancer (precession has since moved the point to Gemini) ancient astronomers presumably  observed that in June Regulus (or Denebola) was not "sinking into the rays of the setting sun" (as one recent writer put it). Leo remained visible (at least in part) after nightfall for a surprisingly long period in June. Because the constellation persisted for many evenings that month, the sun didn't seem to be getting closer and overtaking it. That was near the time of aphelion (July 4). Since the sun was at its slowest, the impression of stopping, while illusory, is understandable. Naturally the ancients came to equate the highest ascent of the sun in the sky with "standing" or apparent near-cessation of movement along the ecliptic.
I assume the ancients noted the opposite effect in January. Earth is at perihelion on January 4, just two weeks after the winter solstice. But whereas the term solstice (Latin for "sun standing") seems appropriate in July, at the start of the year the sun moves relatively rapidly along the ecliptic. The result, of course, is rapid overtaking of planets and stars just to its east at the time. I saw this once when Jupiter was in the evening sky late in December. Over the course of several days the planet's angular distance above the horizon (at nightfall) quickly shrank until it set too soon after sundown to be visible. That's quite a contrast with evening sky celestial objects early in July.

Old Wargame

Across Suez is one of several wargames I used to play. Long predating video games, these board games featured low tech playing counters and maps. Two were about WWII, but those about the Mideast were of particular interest. Sinai was a strategic level wargame as is the one pictured above. Others like IDF were tactical.