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Summary of Lunar Occultations for 1995

More about occultations.

Introduction

During 1995, there are approximately 320 lunar occultations potentially observable from East Anglia, although many involve faint stars. There are three grazing occultations of stars, but no occultations of planets, visible from the region.

This article summarises the circumstances of the best occultations during the year. It provides details for the location of Orwell Park Observatory; differences will in general be negligible for locations throughout East Anglia.

Occultations of Bright Stars

Table 1 lists occultation events during the year, of stars of magnitude 4.0 or brighter, where the circumstances are favourable. These events should be readily visible in small telescopes or binoculars.

The first two columns of the table list the date and time (UT) of the occultation. Column three specifies the phenomenon: "D" denotes a disappearance and "R" a reappearance. The table lists circumstances of D and/or R as dictated by the visibility of each phenomenon (determined by altitude, lunar phase, etc). Column four details the lunar phase (positive waxing and negative waning). Columns five and six give the altitude of the Sun and the star, both in degrees. (A negative solar altitude means that the Sun is below the horizon.) Columns seven and eight provide the star's magnitude and catalogue number.
 

Date
1995
Time
(UT)
D
R
Lunar
Phase
Sun
Alt (°)
Star
Alt (°)
Mag Star
12 Jan22:04
23:10
D
R
0.86+-52
-58
55
48
3.5ε Tau
26 Jan05:34
06:45
D
R
0.27--20
-9
13
17
2.6β Sco
11 Mar
12 Mar
22:53
00:00
D
R
0.73+-39
-42
40
31
3.6λ Gem
18 Mar23:06
23:46
D
R
0.95--37
-39
19
23
1.0Spica
18 Apr03:58D0.90--9164.0ν Sco
12 May19:22D0.94+1181.0Spica
01 Jun21:12D0.11+-873.6λ Gem
12 Jun00:56
02:02
D
R
0.98+-14
-10
13
7
4.0ν Sco
14 Jun23:06
23:43
D
R
0.95--14
-15
12
15
3.9ρ Sgr
08 Aug20:18R0.95+-7164.0ρ Sgr
19 Aug02:19
03:00
D0.40--18
-14
30
37
3.8δ Tau
09 Nov03:52
05:04
D
R
0.97--29
-18
43
32
3.8δ Tau
09 Dec20:51
21:58
D
R
0.93--45
-54
21
31
3.6λ Gem

Table 1. Occultations of stars of magnitude 4.0 or brighter.


The brightest star occulted during the year is the first magnitude star Spica which, in fact, is subject to two occultations, the first on 18 March and the second on 12 May. The second occultation will present a challenge suitable for observers with large telescopes, as the Sun will be just above the horizon at the time of disappearance.

Disappearance Events With A Young Moon

Disappearance events of faint stars with a young Moon represent a challenge for observers with large telescopes. During 1995, there are six disappearance events for which the following criteria hold: Sun 10° or more below horizon; star 10° or more above horizon; lunar phase at most 10%. (A rather arbitrary set of selection criteria!) Table 2 summarises the circumstances. The columns have the same interpretation as those of table 1. In addition, the evenings of Christmas Eve and Christmas Day also offer many disappearance events of faint stars with a relatively young Moon: 23 events over the two evenings with a lunar phase less than 23%.
 

Date
1995
Time
(UT)
D
R
Lunar
Phase
Sun
Alt (°)
Star
Alt (°)
Mag Star
01 Feb17:43D0.04+-10118.0PPM 206268
01 Feb17:51D0.04+-11107.8PPM 206276
01 Feb17:53D0.04+-11109.4PPM 206275
02 Feb18:19D0.09+-151710.7PPM 81593
03 Mar17:35D0.07+-14118.6PPM 238154
02 May20:31D0.08+-101210.6PPM 20476

Table 2. Disappearance events with a young Moon.
 

Grazing Occultations

The tracks of three grazing occultations cross East Anglia during the year. Table 3 summarises the circumstances. Columns one and two give the date and time of the graze and column three specifies the lunar limb involved. Column four indicates the distance between Orwell Park Observatory and point X on the track, on land, where the distance between the two is least; column five links to a plot of the lunar limb profile visible from X. Column six specifies a north or south displacement of the observer's position, relative to the track, based upon inspection of the limb profile, to maximise the chances of witnessing multiple disappearance and reappearance events. Column seven links to an on-line Google Earth plot of the track and column eight links to an off-line image of it. (The plot and image illustrate the nominal track, with no displacement applied.) Column nine details the lunar phase (positive for waxing, negative for waning) and column 10 the altitude of the Sun (a negative solar altitude means that the Sun is below the horizon). Columns 11 and 12 provide the horizontal co-ordinates of the star (azimuth in the order N→E→S→W). Columns 13 and 14 specify the star and its magnitude.
 

Date
1995
Time
(UT)
Limb Dist
OPO
(km)
Limb
Profile
Track
Shift
(km)
Google
Earth
Track
Google
Earth
Image
Lunar
Phase
Sun
Alt
(°)
Star
Alt
(°)
Star
Azi
(°)
Mag Star
14 Oct 05:15 N 26 Profile 2.2 S Track Track 0.73- -10 54 212 6.7 119 Tau
19 Nov 05:22 N 32 Profile 2.0 S Track Track 0.15- -18 18 127 6.7 ZC 1817
11 Dec 23:30 N 86 Profile 4.5 S Track Track 0.80- -60 27 107 4.3 α Cnc, 65 Cnc

Table 3. Grazing lunar occultations.
 


James Appleton