Wednesday, July 22, 2009

Silk tree

Silk tree (Albizia julibrissin) at Crothersville, July 18, 2009.

Link to Albizia julibrissin:

At Crothersville the bright star Vega transits the zenith. Vega is the only major star that transits zenith anywhere in Indiana.

Link to Vega:

Link to zenith:

Vega will transit zenith at any point at latitude 37.7837 degrees north once every sidereal day. From the place of the silk tree this will be a little bit down the road past the middle of Crothersville.

Link to sidereal day:

Tonight, July 22, 2009, Vega transits zenith at Crothersville at 8:21 pm local time.

Link to Vega transit calculator:

1 comment:

Nick said...

That Vega transit time I posted was a mistake. Vega transited zenith at Crothersville 21 minutes after midnight past the evening of July 22. Vega transits zenith about four minutes earlier every day. That is the difference between the sidereal day and the solar day. Vega will transit again at zenith over Crothersville in about an hour from now, that is about 1 minute after midnight which will be the morning of July 27. Vega will transit again that day three minutes before the next midnight. July 27 is the only day in 2009 that Vega transits twice at Crothersville.