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Mon, 29 May 2017 - Eclipsing Binary predictions : 2017 June-August

Here are predictions for eclipses that are reasonably favourable from the UK during June, July and August:

Times are in UT (same as GMT, 1 hour behind BST - so, for example, 22.5h UT is 23.5h BST)

RZ Cassiopeiae

Eclipses last 4.8h, with most of the brightness changes taking place during the middle 3 hours. The times shown below are for the mid-point of the primary eclipses. Eclipses are not quite total, so there is no spell of constant brightness at mid eclipse.

Date Mid-Eclipse (UT)
June 1 0.7h
June 7 0.2h
June 12 23.6h
June 18 23.1h
June 24 22.5h
June 30 21.9h
July 2 2.6h
July 8 2.0h
July 14 1.4h
July 20 0.9h
July 26 0.3h
July 31 23.7h
August 6 23.2h
August 12 22.6h
August 14 3.3h
August 18 22.0h
August 20 2.7h
August 24 21.5h
August 26 2.1h
August 30 20.9h
   

U Cephei

Eclipses last for approx 9 hours. The times shown below are for the primary eclipse mid-point. Eclipses are total, so there is a period of constant brightness around the middle of the eclipse. By August, mid eclipse is occurring during the evening twilight from the UK and so only the brightening from eclipse will be observable

Date Mid-Eclipse (UT)
June 5 1.1h
June 10 0.8h
June 15 0.4h
June 20 0.1h
June 24 23.8h
June 29 23.4h
July 4 23.1h
July 9 22.8h
July 14 22.5h
July 19 22.1h
July 24 21.8h
July 29 21.5h
August 3 21.1h
August 8 20.8h
August 13 20.5h
August 18 20.1h
August 23 19.8h

 

U Coronae Borealis

Corona Borealis is now quite well placed in the evening sky ... but ...  the nights are now too short for the whole eclipse to be observable in one session!

Eclipses last for approx 12 hours. The times shown below are for the primary eclipse mid-point.  Eclipses are not total, so there is no spell of constant brightness around the middle of the eclipse.

Date Mid-Eclipse (UT)
June 11 2.1h
June 17 23.8h
June 24 21.5h
   
July 19 1.5h
July 25 23.2h
August 1 20.9h
   
August 19 3.2h
 August 26 0.9h
   

Beta Lyrae

Beta Lyrae is now wll placed for observation throughout the night.

Both the deeper primary eclipse and less deep secondary eclipse can be followed visually. There is no period of constant brightness between eclipses.

Date Mid-Eclipse (UT)
June 1-2 primary
June 7-8 secondary
June 14-15 primary
June 20-21 secondary
June 27-28 primary
July 3-4 secondary
July 11-12 primary
July 16-17 secondary
July 23-24 primary
July 29-30 secondary
August 5-6 primary
August 11-12 secondary
August 18-19 primary
August 24-25 secondary
August 31-Sep 1 primary

Beta Persei (Algol)

Eclipses last for approx 10 hours. The times shown below are for the primary eclipse mid-point. Eclipses are only partial, so there is no period of constant brightness around the middle of the eclipse.

Although Algol is (just) circumpolar from the UK, it will be too low in the sky during late spring and early summer nights for accurate brightness estimates to be made.

Date Mid-Eclipse (UT)
June 12 1.8h
June 14 22.7h
   
July 5 0.4h
July 7 21.2h
   
July 25 2.1h
July 27 22.9h
   
August 14 3.8h
August 17 0.7h
August 19 21.5h
 

Added by: Tracie Heywood