Seasonal Observability of Cyg OB2 for 2006
This table was produced using John Thorstensen’s Skycalc program.
RA & dec: 20 31 57.0, 41 22 30, epoch 1950.0
Site long&lat: 7 26 28.0 (h.m.s) West, 31 57 12 North.
Shown: Local Date, Moon phase (Full or New), and the hour angle and sec z (air mass) for the object at the following three times:
(1) evening astronomical twilight,
(2) the natural center of night, and
(3) morning astronomical twilight.
The last item is the number of nighttime hours during which the object is at an air mass of less than 3, 2, and 1.5, respectively.
| Date | Moon | Evening Twilight | Mid-night | Morning Twilight | Number of hours
|
|||||
HA |
sec z |
HA |
sec z |
HA |
sec z |
< 3 |
< 2 |
< 1.5 |
||
| 2006 May 12 | F |
-8 50 |
down |
-5 14 |
2.1 |
-1 38 |
1.1 |
4.5 |
3.4 |
2.4 |
| 2006 May 26 | N |
-7 41 |
12.6 |
-4 18 |
1.6 |
-0 55 |
1 |
5.2 |
4.2 |
3.1 |
| 2006 Jun 10 | F |
-6 31 |
3.8 |
-3 16 |
1.3 |
-0 02 |
1 |
6.1 |
5.1 |
4 |
| 2006 Jun 24 | N |
-5 32 |
2.3 |
-2 18 |
1.1 |
0 55 |
1 |
6.4 |
6 |
4.9 |
| 2006 Jul 10 | F |
-4 32 |
1.7 |
-1 12 |
1 |
2 07 |
1.1 |
6.6 |
6.6 |
6.1 |
| 2006 Jul 24 | N |
-3 46 |
1.4 |
-0 16 |
1 |
3 15 |
1.3 |
7 |
7 |
7 |
| 2006 Aug 8 | F |
-3 03 |
1.3 |
0 42 |
1 |
4 28 |
1.7 |
7.5 |
7.5 |
7 |
| 2006 Aug 22 | N |
-2 26 |
1.2 |
1 35 |
1.1 |
5 36 |
2.4 |
8 |
7.5 |
6.4 |
| 2006 Sep 6 | F |
-1 49 |
1.1 |
2 29 |
1.2 |
6 47 |
4.5 |
7.9 |
6.9 |
5.8 |
| 2006 Sep 21 | N |
-1 11 |
1 |
3 23 |
1.3 |
7 57 |
25.1 |
7.3 |
6.3 |
5.2 |
| 2006 Oct 6 | F |
-0 32 |
1 |
4 17 |
1.6 |
9 07 |
down |
6.6 |
5.6 |
4.5 |
| 2006 Oct 21 | N |
0 10 |
1 |
5 13 |
2.1 |
10 16 |
down |
5.9 |
4.9 |
3.8 |
| 2006 Nov 4 | F |
0 53 |
1 |
6 07 |
3 |
11 21 |
down |
5.2 |
4.2 |
3.1 |
| 2006 Nov 20 | N |
1 49 |
1.1 |
7 12 |
6.5 |
-11 24 |
down |
4.3 |
3.3 |
2.2 |
| 2006 Dec 4 | F |
2 43 |
1.2 |
8 12 |
v.low |
-10 18 |
down |
3.4 |
2.4 |
1.3 |
| 2006 Dec 19 | N |
3 47 |
1.4 |
9 18 |
down |
-9 10 |
down |
2.3 |
1.3 |
0.2 |