Castle Point Astronomy Club
1969-2019 - 50th Anniversary Year
Castle Point Astronomy Club Diary
October 2019 by Dave Stratton


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Wednesday 2nd October 2019

Mike said that this Saturday was an Open Night and we should be there for 18.00 or earlier.

He said the venue had changed since our last visit. The scope field is where we did the water rocket launching on our Space Day. He outlined the details and said we must talk to the staff about the leaving procedure to avoid parking charges.

Andrew said that next week would be an Observing Evening or if cloudy Atmospheric Optics by Mike.

He also mentioned that he needs more volunteers for talks.

Jim said we should not forget his equipment which is available to all members.

Ted sad he was still collecting subs.

Mike said a friend has a Vixen 4 inch refractor for sale – tube only. He thought £80 to £100 would secure it. He reminded of his own endeavours with his own Vixen (tube only) - hand held - some time ago and gained nice shots of the ISS.

Peter said our club Star Party at was set for 28th Oct to 4th Nov.

Mike said the business this evening was: Members' Roundup

He started us off with a shot of the last quarter of the Moon – he pointed out two lunar domes that this particular Sun angle showed nicely. They are evidence of volcanic activity.

He mentioned the recent event at Kelling Heath which was blessed with an extraordinary range of weather including some clear skies allowing him to bag some great deep sky objects.

Jim had a lovely image of Abell 84 (PLN 112-10.1) a Planetary Nebula in Cassiopeia.

Also Comet C/2018 N2 (ASASSN) this was discovered a year ago and will reach perihelion next month but will not go much inside the Solar System and will not be brighter than magnitude 11. Plus Comet 260P/McNaught. The distance of it is currently 84,624,996 kilometers, equivalent to 0.565683 Astronomical Units. Light takes 4 minutes and 42.2786 seconds to travel to us.

Jim included finder charts for each of the objects.

Andrew had an image taken with his phone of a purple sky that he had noted it whilst driving and got the pic at his destination n Chelmsford. It was apparently caused by volcanic activity in the southern hemisphere. He also had a shot of a Sun Dog - these are like rainbows that are caused by light refracting through ice crystals and can appear 22.50 degrees either side of the Sun.

Ron had shots from Kelling Heath including a video from inside Andy’s caravan showing torrential rain; however he also had several delightful shots of the starry sky.

Chris had a deep image of the Western Veil Nebula that he had got in three different ways. He said they had needed 50 hours of imaging time.

Peter made a recent visit to Dunsink Observatory in Ireland. It is part of the Dublin Institute for Advanced Studies (DIAS) and integral to the Irish Astronomy Trail, has a long history in the service of science. Research is carried out at Dunsink as part of the programme of research of the Astronomy & Astrophysics Section of the School of Cosmic Physics.

He said he had completed the trip from Southend airport in a single day - attending a meeting there and all for little more than twice the rail fare to London!

He also mentioned his meteor detection camera system that automatically captures anything that moves in field of view - unfortunately this includes wildlife. However he showed us some splendid videos and a composite of meteors over 4.5 hours.

Excellent.

Wednesday 16th October 2019

Andrew said that next week it would be our Gord with a talk: Transits or if it is a clear it will be an Observing Evening.

He also reminded us that on 11th November there is to be a Transit of Mercury a club event is planned so watch this space.

Rob said he had booked the club Christmas lunch for the 12th December at the White Hart.

Andrew said that tonight we were having Astronomers’ Question Time which Mike would manage.

What’s the furthest we can see? A Virtually back to the Big Bang.

How far with an amateur telescope? A Down to 12th Mag. When the light that we see today left Stephan’s Quintet the Earth only had one continent - Alfred Wegener was the one that proposed the theory that the continents were once a single giant landmass that he named 'Pangaea' meaning all lands. Stephan’s Quintet can be seen with a 20 inch scope.

A member has decided to go back to 35mm film for imaging – What is the best setting for the Moon? A 125th at f6, but if using a meter go 2 to 3 steps less than it indicates.

In towns where the street lighting is turned off at night is there a real improvement? A Yes, but there is still a lot of background light; In Southend where lights are not turned off there is still a noticeable improvement in sky brightness when other towns turn theirs off. Neighbouring areas can have a significant effect. Southend Airport does not turn its apron lights off even when there are no aircraft movements. In 1994 in Los Angeles an earthquake caused a major power failure. Many members of the public were alarmed to see the Milky Way and wondered what it was.

There was a transit of Venus in 2012 when is the next? Transits of Venus are among the rarest of predictable astronomical phenomena. They occur in a pattern that generally repeats every 243 years, with pairs of transits eight years apart separated by long gaps. The next transits of Venus will take place on 10–11 December 2117 and 8 December 2125.

What f ratio is required to get the Pleiades in an eyepiece view? It’s best to use bins or a very low power with a scope.

What is the best configuration for a 6inch Newtonian? An f ratio of 8 will give a good all round instrument.

Shouldn’t we be looking for life on other planets? Exoplanets are already being studied to this end as is Mars. Amino Acids have been found which are ‘the building blocks of life’.

How much bigger would Jupiter have to be to be a star? Jupiter would need to be 80 – 100 times larger. 8 – 10% of the Sun’s mass is the minimum.

What is the highest anyone has been on the planet? Not counting planes etc. His is 16,000feet on Kilimanjaro he could see the Southern Cross and the Plough at the same time. Altitude really helps us to see the sky, but it also reduces O2 levels in the blood and the first sense to suffer is the eyes. Apparently a quick whiff of Oxygen can help significantly and also deliberately hyper ventilating.

What can be done about intrusive security lighting? Sometimes a temporary screen that can be mounted on your perimeter can help a lot. There was much discussion about the apparent fact that street lighting is controlled by text messaging as individuals or en-mass.

Saturn has had more moons discovered by the Cassini Probe and now has more that Jupiter – but they still look the same – why?

The newer discoveries are all small and not visible in amateur scopes so we are unaffected.

Excellent and informative.

23rd October 2019

Andrew said he was in the process of revamping our yahoo group. He had put round an email so just follow the instructions to sign up.

He added that next week we have Ed with Observing Highlights for November and December.

Jim said he has loads of kit available to members.

Andrew introduced our Gord for his talk: Transits

Gord began by showing us a grazing transit of Mercury on Jupiter on 12th November 1999.

He mentioned that lunar transits are called eclipses.

He explained why we do not get a transit every orbit of Mercury. The orbit path is tilted to the ecliptic we only get a transit when the node is on the ecliptic.

The months May and November are the most likely and the chances improve every seven years.

Venus transits are most likely in December and June in pairs eight years apart. The last transit of Venus was on 5 and 6 June 2012 and was the last Venus transit of the 21st century; the prior transit took place on 8 June 2004. The previous pair of transits were in December 1874 and December 1882. The next transits of Venus will take place on 10–11 December 2117 and 8 December 2125.

Transits of Mercury occur in May or November. The last four transits occurred on November 15, 1999; May 7, 2003; November 8, 2006; and May 9, 2016. The next will occur on November 11, 2019, and then on November 13, 2032. A typical transit lasts several hours.

Gord showed us a map of the entire Earth depicting the path on ingress for the upcoming eclipse.

The transit on 11th November will start at 12.34 and still be in progress as the sun sets at 16.15.

He said that to see the phenomena you will need a clear sky, good filters and the right magnification.

Gord explained the term 1st contact - when the planet just appears to touch the sun’s disc, 2nd contact when it is just completely on the disc, 3rd contact when it is only just still on the disc immediately prior to leaving and 4th contact when it just leaves the disc. Actually measuring the time is complicated by the black-drop effect. He gave a simple demonstration of the effect by suggesting we hold our thumb and forefinger such that they are very nearly touching. When viewed against a bright background they tend to merge.

With the aid of a diagram he explained that observers on different sides off the Earth will see the eclipse at different times.

Among the earliest large scale international scientific collaborations were expeditions in 1761 and again in 1769 to observe the transits of Venus.

Expeditions sent to widely different locations tried to make accurate observations of the contact times.

In 1761 – Siberia, Newfoundland, Madascaskar, India, Cape of Good Hope, St Helena and St Petersburg.

In 1769 – Tahiti, Norway, Hudson’s Bay, New England, Baja and California.

Due to the frustrations caused by the Black-drop effect the results were perhaps dubious but we now know that they were within 3%.

Gord treated us to a nice image of the Moon transiting the Earth. Another of the ISS and Venus transiting the Sun together. Also the ISS transiting the Moon.

An image of Saturn with four of its moons transiting. We saw transits on Neptune and multiples on Jupiter.

In astronomy, an analemma from Greek anal?mma "support") is a diagram showing the position of the Sun in the sky, as seen from a fixed location on Earth at the same mean solar time, as that position varies over the course of a year. The diagram will resemble the figure 8.

Gord gave us some dates for our diaries:

On 22nd November 2065 Venus will transit Jupiter.

If you happen to be on Mars on 10th November 2084 then you will see the Earth and the Moon transit the Sun.

Both Mercury and Venus will transit the Sun on 29th July 69163.

As seen from Mars the Earth and Venus will transit the Sun in 571,471.

Terrific.

30th October 2019

Andrew said the new club email group was up and running - any problems let him know.

He said that next week we have Jackie Burns an outside speaker talking about her Space Art.

Jim spoke about our new website and showed several pages from it including the Gallery. Andrew said the Diary was work in progress but getting there. There is a page of useful links.

The address is cpastro.club. Mike said the name has been changed because we were getting blocked due to the name being similar to a dodgy site elsewhere.

Mike introduced Ed for his talk: Observing Highlights for November and December

Ed began with an update on our Wallasea Island site. The license has been renewed with some improvements. We are now allowed seven hours - an extra two. Also we can register a need to go as late as 11.00 on the day. He showed a map of the location giving the post code as SS4 2HD.

He showed us a chart of the sky and briefly pointed out the area he was covering.

He began with Almach (Gamma Andromedae), which appears in a telescope as one of the finest double stars in all the heavens. One component of this telescopic double appears golden, and the other appears indigo blue. What’s more, further research has shown that Almach is really four stars.

He then moved to NGC 891 it is an edge-on unbarred spiral galaxy about 30 million light-years away in the constellation Andromeda. It was discovered by William Herschel on October 6, 1784. It has a good dust lane that can be readily seen with a 16 inch scope.

He then showed us M34 it is an open cluster in the constellation Perseus. It was probably discovered by Giovanni Batista Hodierna before 1654 and included by Charles Messier in his catalog of comet-like objects in 1764. It is 1500 lya.

Ed then told us about Algol it is a three-star system, consisting of in which the hot luminous primary and the larger, but cooler and fainter component regularly pass in front of each other, causing eclipses. Thus Algol's magnitude is usually near-constant at 2.1, but regularly dips to 3.4 every 2.86 days during the roughly 10-hour-long partial eclipses. The secondary eclipse when the brighter primary star occults the fainter secondary is very shallow and can only be detected photo electrically. He said the main change can readily be detected by the naked eye. It is 93 lya.

He gave the details if the timings for the next two months.

He told us about comet C/2017 T2 (PANSTARRS) was discovered at 20th magnitude in September 2017 when it was it was 9.3 au from the Sun. It is heading for a perihelion at 1.6 au in early May 2020. The comet is currently in conjunction but it was apparently brightening rapidly when last seen in April. It should become visible from the UK in mid July very low in the morning sky as it moves slowly NE in Taurus. By then it will be 3.8 au from the Sun and 4.5 au from the Earth. It moves higher in the sky and will be visible throughout the autumn, winter and spring as a circumpolar object and it remains well placed in Ursa Major at perihelion.

Ed said The famous Geminid meteor shower will give bright shooting stars this winter, though a just-past-full moon will make all but the brightest hard to see. The shower will peak on Dec. 13-14, according to NASA meteor expert Bill Cooke. Even after the peak, bright meteors may be visible for the next few days.

The Geminids are considered one of the best meteor showers every year because the individual meteors are bright, and they come fast and furious. This year, because of the moonlight, around 20-30 may be visible per hour.

He said that on 11th November we will be treated to a conjunction of Saturn and Venus – he showed us a chart of their movements up to the closest. You will need a good SW horizon.

Ed showed us a chart showing the location of Vesta the brightest asteroid which will be at opposition on 12th November.

We saw a chart depicting the retrograde motion of Uranus from 1st November to 1st Mar 2020.

Johannes Kepler December 27, 1571 – November 15, 1630 was a German astronomer, mathematician, and astrologer. He is a key figure in the 17th-century scientific revolution, best known for his laws of planetary motion. He worked out that the swept area of a planet’s orbit was always the same regardless of the planet’s position in the orbit.

He predicted transits of Mercury and Venus in 1631 but sadly died before they happened.

Ed showed us a chart listing the Mercury transits from 2001 until 2100.

He showed us a drawing he made of the transit of 9th May 2016 and said how delighted he was to actually see the first indent of the planet within 1 minute of the predicted time.

He said the upcoming transit on 11th November would begin at 12.35. He said that Mary had invited us to her garden to see the event as a group.

Ed spent some time going over the precautions necessary to safely look at the Sun.

He had a handout giving some details of what he had spoken of.

First class.


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