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PostPosted: Thu Oct 12, 2017 9:32 am 
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Joined: Sun May 11, 2008 6:11 pm
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Location: Portslade, Sussex Lat 50deg 51min Long 0deg 13mins West
11th & 12th October 2017: 2310-2330 BST & 0255-0305 BST: Used 10x50 mono and 22x60 spotter. Conditions were very good, the evening rain-clouds having surprisingly cleared, with Last-Quarter Moon not rising till the end of the first session. The Moon was high in the East for the second session, but Aries was very high in the south, and the Moon did not interfere even then. The position was taken from a chart in an astronomy magazine, checked against "Heavens Above" and plotted on Map 79 of Uranometria. I worked up from Hamal (alpha Arietis), to a squashed-inverted- mini-plough" asterism which included stars 11, 14, 16, 20 and 21 Arietis. The last two acted as "pointers" down to a row of 6th & 7th magnitude stars. Asteroid [7] IRIS was between the lowest star and a triangle of fainter stars above. regards maf


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PostPosted: Fri Oct 13, 2017 1:13 pm 
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Joined: Sun May 11, 2008 6:11 pm
Posts: 2784
Location: Portslade, Sussex Lat 50deg 51min Long 0deg 13mins West
12th-13th October 2017:
2030-2110 BST. Despite light pollution and low altitude of target, it was possible to use the 22x60 spotter at the back-door to locate Hamal and most of the field stars and then asteroid (7) IRIS. Some movement was noticeable since last time. The asteroid could also be seen in 10x50 monocular when rested on the door-frame.
0035-0050 BST: Awoke to find the sky transparency was very good, but with swathes of foggy-cloud sweeping the sky from time to time. To the back-garden with 22x60 and was immediately able to locate Iris and its environs, and additional very faint field stars were visible, including an arrow-shaped or tiny waterjar-shaped asterism towards which the asteroid was moving. At 0045 BST the bright arc of the rising Moon could be seen between the bushes, then part of the Moon itself and by 0050 the foggy-cloud had completely covered the sky, and so I went in. It cleared once again later, so I popped out at 0125 BST with the 10x50 monocular in hand for a final look...then I went back to bed! regards maf
13th October 2017: 2121-2130 BST: Clouds began to clear. Used the 22x60 (as before) to locate (7) Iris, with little difficulty. Obvious movement from last sighting. Followed until 2130 BST but then fast-moving foggy-cloud rushed across the sky. This cleared again eventually but left a stubborn piece of higher, slower cloud just in the wrong place. By 2200 BST, this had moved off and so replacing the 22x60 with the Endurance 12-36x50, I took for a final look, and then went to bed. regards maf


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PostPosted: Sun Oct 15, 2017 9:30 am 
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Joined: Sun May 11, 2008 6:11 pm
Posts: 2784
Location: Portslade, Sussex Lat 50deg 51min Long 0deg 13mins West
15th October 2017: 0125-0142 BST: Awoke to find that the evening fog had dispersed and transparency was good. Aries was high in tHe south. Asteroid (7) Iris was easily found in 22x60, just below the lowest faint star of the "arrowhead or very small waterjar" asterism. 0445-0600 BST: Crescent Moon with Earthshine and near to Regulus, was in the east, so went outside again, this time withe Endurance 12-36x50 spotting scope on a light-weight tripod. With Aries now in the west, locating Iris required that I venture with the scope onto the small lawn, which was very wet. From there I could observe the asteroid over the roof of my house, which I did. It was also visible from the west-facing front-room window, without having to stand in the wet grass, so continued from there until 0600 BST. Iris was gradually creeping away from the lowest star of the tiny asterism. (This asterism is shown on Map 38 of the Interstellarum Deep Sky Atlas, about half-a-degree below the star labelled Sigma 240. It is also shown in Uranometria, with the stars being shown at about 9th or 9.5 magnitude.)

15th October 2017: 2110-2125 BT: Unusually warm, but with very poor transparency low down. I could jusy about make out Hamal with the unaided eye. Using 12-36x50 Endurance spotting scope from the backdoor enabled a view of the brightest field stars but not the "micro-waterjar", but Iris was clearly located now heading towards a little elongated asterism of a few stars. These stars are somewhat brighter than the previously mentioned asterism.
regards maf.

16th October 2017:0502 + 0520 BST: Large gaps in messy clouds, with only two possible views of Iris, using Endurance again from the lawn, and seen above the house roof, and also saw the "new" asterism. regards maf


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