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It's very interesting this comparison.
The great advantage I see is that Tycho has measured almost every star down
to 11 magnitude and now we have data on each of them. But another look at the
uncertainties suggests that it's better to trust in PEPV from the ground
whenever available.
All the examples I gave were found by me just by observing, so this means
that the differences are obvious even visually.
Another last question:
I don't understand the reason why such big discrepancies exist in VT and BT
magnitudes. If it's about data reduction I can understand that different
reductions turn out with different corrected V magnitudes, but aren't VT
and BT Tycho magnitudes the intrinsic measurements taken during the mission? In
the case I presented for TYC 8659-00930-1 colours and magnitudes seem to
belong to different stars:
TYCHO 1 = BT 10.95 VT 10.15 B-V
0.71 V 10.07 --- TYCHO 2 = BT
10.99 VT 10.80 B-V 0.16 V
10.78
What are the original values?
Thanks and best wishes.
Sebastian Otero.
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