Sometimes bad astronomy can come from astronomers too, when maybe a debunking-agenda becomes more important than respect for accurate astronomy.

As part of an effort to debunk the mistaken archaeology of Bauval and Hancock (B&H), the astronomer Anthony Fairall said that, in 10,500 BC, the vernal equinox wasn't in Leo (as B&H claimed), but, rather was within the modern boundaries of Virgo.

Fairall even gave the 2000 equatorial co-ordinates for the position of the 10,500 BC vernal equinox:

Right Ascension: 11h 40m

Declination: +2.2 degrees

Ed Krupp is said to have verified Fairall's result, by means of a planetarium.

The problem:

That's exactly the position that you get if you incorrectly assume that the precession has always had its current rate, of 50.28 or 50.29 arcseconds per Julian year.

But that incorrect constant-rate assumption gave the debunking result that Fairall wanted. Is that why Fairall used it, even though it was based on a constant precession-rate that Fairall must have known is incorrect? Fairall is a professional, PhD astronomer, after all.

Taking rate-variation into account gives, for 10,500 BC, a vernal equinox-position in Leo.

I feel that scientific accuracy should be taken seriously, and that the desire to debunk doesn't justify intentional bad astronomy by an astronomer.

I don't subscrbe to Bauval's or Hancock's theories, but i find it disapppointing that professional astronomers would intentionally use erroneous astronomy for debunking purposes.

I feel that, when professional astronomers falsify astronomy, for some social agenda such as debunking, they're abusing their position of authority and public trust.

I'm not saying that the matter of where the vernal equinox was in 10,500 BC is a crucial matter. But I mention it because it shows two astonomer's disappointing abuse of their position of authority and public trust.

By the most "Fairall-favoring" of Jaques Laskar's precession-rate curves, the precession-rate around 10,500 BC was 49 arcseconds per Julian year. Using, over the interval between now and 10,500 BC, the average of 49 and 50.28 amounts to a linear approximation to the rate.

Because the curve is upward-curving over that entire interval, that linear approximation overestimates the amount of precession, and gives an overly eastward position of the 10,500 BC vernal equinox. In other words, it portrays that equinox as being more toward Virgo, and less toward Leo.

But nevertheless, that linear approximation, that average (49 + 50.28)/2 rate, shows sthe 10,500 BC vernal equinox to have been well within the boundaries of modern Leo.

Additionally, when Denebola's (westward) proper motion is considered, it's found that, in 10,500 BC, the vernal equinox was within the range of ecliptic longitudes encompassed by Leo's sickle-and-right-triangle asterism.

To summarze: By Laskar's precession-rate curves, and considering Denebola's proper motion, the 10,500 BC vernal equinox was in Leo, by any standard or interpretation.

It's newsworthy when, on an astronomical question, two popular writers, Bauval and Hancock are right, and two PhD professional astroomers, Fairall and Krupp, are wrong.

Surely bad astronomy is bad even if it's perpetrated by professional astronmers (isn't it even worse then?)

Surely the goal of debunking doesn't justify falsifhying astronomical facts.