2018 Edition Updates

To report other corrections or to make suggestions for improvement, please send an email message to Handbook Editor.

On p. 11, the longitude details for Mont Mégantic Observatory should be 71°09′W and elevation should be 1095/3592

On p. 114, in Mercury, the first sentence should read "Visible for the first few days in morning twilight for northern observers..."

On p. 160, mention is made of Joshua Slocum. It should be Frederick Slocum, 1873 – 1944, and he was not a Canadian. 

On p. 167, the date for the occultation of ZC 3268 should be Jan. 20

On p. 187, the page reference for EPHEMERIS FOR THE SUN should be p. 185.

On p. 225, the GRS calculation is incorrect; it should read:

The table may also be used to estimate when the Great Red Spot (GRS) will cross the central meridian
of Jupiter’s disk. (Based on drift measurements, the GRS is predicted to be near longitude 284.5° in System II on 2018 Jan. 0, drifting by about +14.5° per year. See jupos.privat.t-online.de for an up-to-date value.)
Example: Suppose an observer in Montréal is viewing Jupiter on the evening of Apr. 2 (time zone: EDT,
−4 h). At 0 h UT Apr. 3 (20 h EDT Apr. 2), the table gives 222.1° for the longitude of the central meridian in System II. Ignoring GRS drift, a further rotation of 284.5°– 221.1°= 63.4° will bring the GRS to the central meridian, which takes place 63.4°÷ 36.259°/ h = 1.75 h = 1 h 45 min later. Thus the GRS will transit at 1:45 UT Apr. 3 = 21:45 EDT Apr. 2. (Correcting for the annual drift in GRS longitude would add 14.5° × 3/12 ÷ 36.259°/ h = 0.10 h, or 6 min to the transit time.)

Last modified: 
Friday, June 8, 2018 - 4:45pm