Alachua Astronomy Club: Transit of Mercury: November 1999

	Alachua Astronomy Club, Inc.	Member Astronomical League	Member International Dark-Sky Association
	Transit of Mercury November 1999	Member Astronomical League	Member International Dark-Sky Association
	29°39' N, 82°21' W Altitude: 50 Meters (more or less)		Updated Nov. 12, 1999
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Transit of Mercury across Sun

1999 November 15

Mercury will transit (cross) the extreme N-NE limb of the Sun on Monday, November 15, 1999.

In Gainesville, Florida this event will begin about an hour and twenty minutes before sunset when the Sun is low over the southwest horizon and end about 25 minutes before sunset. (The Sun will set about 5:34 p.m. EST in Gainesville.) Hence, observers will need a very clear view of the southwest sky free of haze, clouds and obstructions (trees, buildings, etc.).

This is the first transit of Mercury across the Sun since 1993 and the first one for the United States since 1973. Only thirteen transits of Mercury willl have occurred in the 20th century. For more information about this event including times for other locations see:

1999 Transit of Mercury by Fred Espenak (lists transit times for various cities)
A Most Unusual Graze: The Transit of Mercury on 1999 Nov 15 by John E. Westfall
Moondark for November: Transits by Douglas C. Miller
Transit of Mercury (Live on Videocam?)

The above animation show Mercury crossing the extreme north-northeast solar disk as viewed from Gainesville, Florida. The tiny disk of Mercury will cross from left to right as you see it in this animation. (The view from most other locations in the USA will be similar.) This animation assumes one is looking through a telescope that does not invert or reverse the image.
Note: Animation may take several seconds to a minute or more to load and run if your internet connection is slow.

– Angular diameter of Mercury's disk = 9.9 arc seconds.
– Approximate maximum separation between Mercury's limb (edge) and Sun's limb = 6 arc sec (for Gainesville, FL).

Approximate Transit Times for Gainesville, Florida

Transit begins
Maximum separation
Transit ends

4:11 p.m. EST (Sun's altitude 15 degrees)
4:41 p.m. EST (Sun's altitude 10 degrees; azimuth 28 degrees S of W)
5:10 p.m. EST (Sun's altitude 4 degrees)

WARNING

Looking at the exposed disk of the Sun is very dangerous—irreparable eye damage may result.

"Dark filters" may not afford adequate protection since they may transmit invisible ultraviolet and infrared rays.

The best and safest way to observe this event is to join with observers from either the Alachua Astronomy Club, Inc. or the UF Department of Astronomy.

(Come to either viewing location below late Monday afternoon, November 15, 1999 soon after 4:00 p.m. EST.)

Alachua Astronomy Club, Inc. Observing Location: Club members will be teaming up with the students in the Santa Fe Community College Science Club to observe this event. The club will provide telescopes for safe viewing of this rare event. The viewing spot is the SFCC athletic field at the southern end of the Sante Fe Community College Northwest Campus, 3000 NW 83 Street. (The athletic fields border NW 23 Avenue and NW 83 Street — see map.)

Department of Astronomy Observing Location: The Department will have a solar telescope in Room 401, Bryant Space Science Building (see map on the UF Campus.

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Approximate Transit Times for Gainesville, Florida
Transit begins Maximum separation Transit ends	4:11 p.m. EST (Sun's altitude 15 degrees) 4:41 p.m. EST (Sun's altitude 10 degrees; azimuth 28 degrees S of W) 5:10 p.m. EST (Sun's altitude 4 degrees)