DaveGee
01-02-2008, 07:41 PM
Greetings Everyone,
There is to be a great opportunity to observe the Lunar Occultation of Antares tomorrow (Saturday 2nd Feb) morning. The disappearance against the bright lunar limb will be a sight to remember however it's the reappearance of the star at the dark lunar limb will be spectacular to say the least! Antares' mag. 5.4 secondary component will emerge first and nearly 6 seconds will elapse before the primary will emerge from behind the limb. Normally the secondary is a fairly difficult component to see because of the primary star's luminance but not when the primary is hidden behind the lunar limb!
The times of disappearance and reappearance will vary depending on your location. Observers in North Queensland and Auckland can experience a grazing occultation!
Please consult the list below for times for a capital city closest to you. REMEMBER the times are in Universal Time (UT) and you will need to convert the predicted times to your local times. For example. For an observer in Sydney the Disappearance will occur at;
1st February 16:09:24UT so, simply add 11 hours to calculate the local time as 3:09:24AM on 2nd February. (16UT+11hours=27hours then 27-24= 3am on February 2nd)
I am particularly interested in receiving accurate timings of the reappearance by observers using video cameras and GPS based timing equipment (esp. KIWI-OSD) If I can get two or more good timings of the reappearance of both components observed from widely spaced locations then I hope to determine accurate figures for the separation and position angle of the component pair. (these will be also used in the tutorial session of the 2TTSO)
I have uploaded some maps of the moon showing D and R sites for Capital cities listed below... See...
http://users.tpg.com.au/users/daveg/occ_maps/Adelaide_Moon.png
http://users.tpg.com.au/users/daveg/occ_maps/Melbourne_Moon.png
http://users.tpg.com.au/users/daveg/occ_maps/Sydney_Moon.png
http://users.tpg.com.au/users/daveg/occ_maps/Brisbane_Moon.png
http://users.tpg.com.au/users/daveg/occ_maps/Auckland_Moon.png
http://users.tpg.com.au/users/daveg/occ_maps/Wellington_Moon.png
You will need to carefully estimate the reappearance site by measuring the position angle (PA) around the lunar limb or by carefully noting the craters depicted on the maps and point your telescope at that site and wait for the stars to pop out.
Here is a video of an AntaresR I made in 2006...
http://www.youtube.com/watch?v=W09GACXhoY4
Good luck and clear skies.
Regards
DaveGault
-----------------------------------------------------------------------------
ZC2366 = Antares = alpha Scorpii
2366 is double: 1.0 5.4 2.5" 273.7
2366 = alf Sco, 0.88 to 1.16V, Type LC
Occultation prediction for Adelaide, SA
E. Longitude 138 36, Latitude -34 55
day Time P Star Sp Mag Mag % Elon Sun Moon CA PA VA
y m d h m s No D v r V ill Alt Alt Az o o o
08 Feb 1 16 10 24 D 2366dM1 1.1 0.1v 27- 63 11 115 -86S 101 224
08 Feb 1 17 8 19 R 2366dM1 1.1 0.1v 27- 62 22 108 72N 294 53
Occultation prediction for Brisbane, QLD
E. Longitude 153 3, Latitude -27 28
day Time P Star Sp Mag Mag % Elon Sun Moon CA PA VA
y m d h m s No D v r V ill Alt Alt Az o o o
08 Feb 1 16 7 14 D 2366dM1 1.1 0.1v 27- 63 19 111 -54N 60 172
08 Feb 1 16 48 16 R 2366dM1 1.1 0.1v 27- 62 28 107 27N 339 88
Occultation prediction for Sydney, NSW
E. Longitude 151 4, Latitude -33 50
day Time P Star Sp Mag Mag % Elon Sun Moon CA PA VA
y m d h m s No D v r V ill Alt Alt Az o o o
08 Feb 1 16 9 24 D 2366dM1 1.1 0.1v 27- 63 20 109 -75N 82 200
08 Feb 1 17 5 36 R 2366dM1 1.1 0.1v 27- 62 31 103 50N 316 71
Occultation prediction for Melbourne, VIC
E. Longitude 144 58, Latitude -37 49
day Time P Star Sp Mag Mag % Elon Sun Moon CA PA VA
y m d h m s No D v r V ill Alt Alt Az o o o
08 Feb 1 16 13 13 D 2366dM1 1.1 0.1v 27- 63 17 110 -88S 98 222
08 Feb 1 17 13 32 R 2366dM1 1.1 0.1v 27- 62 29 103 69N 297 58
Occultation prediction for NZ Auckland
E. Longitude 174 46, Latitude -36 52
day Time P Star Sp Mag Mag % Elon Sun Moon CA PA VA
y m d h m s No D v r V ill Alt Alt Az o o o
08 Feb 1 16 46 57 D 2366dM1 1.1 0.1v 27- 63 -10 47 91 -25N 32 148
08 Feb 1 16 54 6 Gr 2366dM1 1.1 0.1v 27- 62 -9 48
** GRAZE: CA-13.3N; Dist. 45km in az. 38deg. [Lat =-36.36-0.62(E.Long-174.77)]
08 Feb 1 17 2 59 R 2366dM1 1.1 0.1v 27- 62 -7 50 88 -1N 7 124
Occultation prediction for NZ Wellington
E. Longitude 174 46, Latitude -41 17
day Time P Star Sp Mag Mag % Elon Sun Moon CA PA VA
y m d h m s No D v r V ill Alt Alt Az o o o
08 Feb 1 16 40 2 D 2366dM1 1.1 0.1v 27- 63 -9 45 87 -51N 57 180
08 Feb 1 17 27 40 R 2366dM1 1.1 0.1v 27- 62 -1 54 78 26N 340 104
There is to be a great opportunity to observe the Lunar Occultation of Antares tomorrow (Saturday 2nd Feb) morning. The disappearance against the bright lunar limb will be a sight to remember however it's the reappearance of the star at the dark lunar limb will be spectacular to say the least! Antares' mag. 5.4 secondary component will emerge first and nearly 6 seconds will elapse before the primary will emerge from behind the limb. Normally the secondary is a fairly difficult component to see because of the primary star's luminance but not when the primary is hidden behind the lunar limb!
The times of disappearance and reappearance will vary depending on your location. Observers in North Queensland and Auckland can experience a grazing occultation!
Please consult the list below for times for a capital city closest to you. REMEMBER the times are in Universal Time (UT) and you will need to convert the predicted times to your local times. For example. For an observer in Sydney the Disappearance will occur at;
1st February 16:09:24UT so, simply add 11 hours to calculate the local time as 3:09:24AM on 2nd February. (16UT+11hours=27hours then 27-24= 3am on February 2nd)
I am particularly interested in receiving accurate timings of the reappearance by observers using video cameras and GPS based timing equipment (esp. KIWI-OSD) If I can get two or more good timings of the reappearance of both components observed from widely spaced locations then I hope to determine accurate figures for the separation and position angle of the component pair. (these will be also used in the tutorial session of the 2TTSO)
I have uploaded some maps of the moon showing D and R sites for Capital cities listed below... See...
http://users.tpg.com.au/users/daveg/occ_maps/Adelaide_Moon.png
http://users.tpg.com.au/users/daveg/occ_maps/Melbourne_Moon.png
http://users.tpg.com.au/users/daveg/occ_maps/Sydney_Moon.png
http://users.tpg.com.au/users/daveg/occ_maps/Brisbane_Moon.png
http://users.tpg.com.au/users/daveg/occ_maps/Auckland_Moon.png
http://users.tpg.com.au/users/daveg/occ_maps/Wellington_Moon.png
You will need to carefully estimate the reappearance site by measuring the position angle (PA) around the lunar limb or by carefully noting the craters depicted on the maps and point your telescope at that site and wait for the stars to pop out.
Here is a video of an AntaresR I made in 2006...
http://www.youtube.com/watch?v=W09GACXhoY4
Good luck and clear skies.
Regards
DaveGault
-----------------------------------------------------------------------------
ZC2366 = Antares = alpha Scorpii
2366 is double: 1.0 5.4 2.5" 273.7
2366 = alf Sco, 0.88 to 1.16V, Type LC
Occultation prediction for Adelaide, SA
E. Longitude 138 36, Latitude -34 55
day Time P Star Sp Mag Mag % Elon Sun Moon CA PA VA
y m d h m s No D v r V ill Alt Alt Az o o o
08 Feb 1 16 10 24 D 2366dM1 1.1 0.1v 27- 63 11 115 -86S 101 224
08 Feb 1 17 8 19 R 2366dM1 1.1 0.1v 27- 62 22 108 72N 294 53
Occultation prediction for Brisbane, QLD
E. Longitude 153 3, Latitude -27 28
day Time P Star Sp Mag Mag % Elon Sun Moon CA PA VA
y m d h m s No D v r V ill Alt Alt Az o o o
08 Feb 1 16 7 14 D 2366dM1 1.1 0.1v 27- 63 19 111 -54N 60 172
08 Feb 1 16 48 16 R 2366dM1 1.1 0.1v 27- 62 28 107 27N 339 88
Occultation prediction for Sydney, NSW
E. Longitude 151 4, Latitude -33 50
day Time P Star Sp Mag Mag % Elon Sun Moon CA PA VA
y m d h m s No D v r V ill Alt Alt Az o o o
08 Feb 1 16 9 24 D 2366dM1 1.1 0.1v 27- 63 20 109 -75N 82 200
08 Feb 1 17 5 36 R 2366dM1 1.1 0.1v 27- 62 31 103 50N 316 71
Occultation prediction for Melbourne, VIC
E. Longitude 144 58, Latitude -37 49
day Time P Star Sp Mag Mag % Elon Sun Moon CA PA VA
y m d h m s No D v r V ill Alt Alt Az o o o
08 Feb 1 16 13 13 D 2366dM1 1.1 0.1v 27- 63 17 110 -88S 98 222
08 Feb 1 17 13 32 R 2366dM1 1.1 0.1v 27- 62 29 103 69N 297 58
Occultation prediction for NZ Auckland
E. Longitude 174 46, Latitude -36 52
day Time P Star Sp Mag Mag % Elon Sun Moon CA PA VA
y m d h m s No D v r V ill Alt Alt Az o o o
08 Feb 1 16 46 57 D 2366dM1 1.1 0.1v 27- 63 -10 47 91 -25N 32 148
08 Feb 1 16 54 6 Gr 2366dM1 1.1 0.1v 27- 62 -9 48
** GRAZE: CA-13.3N; Dist. 45km in az. 38deg. [Lat =-36.36-0.62(E.Long-174.77)]
08 Feb 1 17 2 59 R 2366dM1 1.1 0.1v 27- 62 -7 50 88 -1N 7 124
Occultation prediction for NZ Wellington
E. Longitude 174 46, Latitude -41 17
day Time P Star Sp Mag Mag % Elon Sun Moon CA PA VA
y m d h m s No D v r V ill Alt Alt Az o o o
08 Feb 1 16 40 2 D 2366dM1 1.1 0.1v 27- 63 -9 45 87 -51N 57 180
08 Feb 1 17 27 40 R 2366dM1 1.1 0.1v 27- 62 -1 54 78 26N 340 104