Castle Point Astronomy Club
1969-2019 - 50th Anniversary Year
Castle Point Astronomy Club Diary
December 2017 by Dave Stratton

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Wednesday 6th December 2017

Andrew said that next week was our Christmas Social.

Mike introduced Peter for his Observing Highlights - December 2017

Peter began by saying that he loves meteor watching. He showed an image of a very bright meteor.

He explained that little chunks of rock and debris in space are called meteoroids. They become meteors, or shooting stars, when they fall through the atmosphere; leaving a bright trail as they are heated to incandescence by the friction of the atmosphere. Pieces that survive the journey and hit the ground are called meteorites.

Meteors are typically associated with the orbit path of a comet. Peter said the parent body for the Geminids is an asteroid, 3200 Phaeton. It was only discovered in 1963 from images taken from spacecraft. It comes closer to the Sun than any other named asteroid. Its orbit is 1.43 years it is 3 miles across and on 16th December it will be pass the Sun at 6.3 million miles distance.

Larger meteors are called fireballs and can be very bright, better than magnitude 5.

The Geminids, which are due very shortly on 13/14th December, can have a Zenith Hourly Rate (ZHR) of 100 and there tend to be some fireballs.

We saw a clip showing Phaeton moving across the sky and another showing its path and phase.

He showed us a chart showing the position of the radiant in Gemini.

It is remarkable that the ZHR was about 40 when they were first seen in 1861 and have increased every year since and may well reach 120 this time around.

There is a Club meteor watch planned for the event, following our normal meeting, to our Dark Site. He said he would put the details on our email group.

Mike introduced Jane for her occasional Item on Astro News

She began with Vinyl Frontier where you can get a copy of the Voyage Golden Record that was sent in the direction of Luyten´s Star. There is planned to be something better in 2018 and public participation is requested.

She mentioned that the Comet 67P was known as the Rubber Duck because of its distinctive shape. She said that a new asteroid has been called ´Oumuamua, formally designated 1I/2017 U1, is the first known interstellar object to pass through the Solar System. It was discovered by Robert Weryk using the Pan-STARRS telescope on 19 October 2017, 40 days after it passed its closest point to the Sun. When first seen, it was about 33,000,000km from Earth (about 85 times as far away as the Moon), and already heading away from the Sun. Initially assumed to be a comet, it was reclassified as an asteroid a week later, then the first of a new class of interstellar objects.

´Oumuamua is a relatively small object, estimated to be 30-180 metres in size. It is dark and very red, similar to objects in the outer Solar System. It is moving so fast relative to the Sun that there is no chance it originated in the Solar System, nor can it be captured into orbit, so it will eventually leave the Solar System and resume traveling in interstellar space. Oumuamua´s system of origin, and the amount of time the object has been traveling among the stars in the galactic disc, remain unknown.

The Dubai Air Show got a mention as it is a centre for space agriculture, having space food like lettuce and strawberries.

A lady from Vietnam got a mention. She has been employed by NASA making clothing for astronauts.

There has been a Dark Sky Conference in Scotland and we saw a map showing the location of the so designated sites.

She mentioned some reading material:-Scott Kelly is a twin who spent a year in space and his twin brother who did not Scott wrote ‘Endurance’ a book about his experience.

Tim Peake has a book called ‘Ask an Astronaut’. Also Helen Sharman has one called ‘Seize the Moment’.

Jane ended with some fun pressies from a site called ‘Naughty but Nice’. Great fun.

Mike introduced Dave Smith for a talk on Me and My Scope

Dave said that he had been imaging and therefore not doing direct observing for 5 years. When he was at Kelling Heath this year he took binoculars. He had decided to correct this so he got a 12 inch Dob by SkyWatcher. Sadly he found it to be just too heavy for him to deal with, however the shop were happy to allow him to take it back and swop it for what he had in front of us. A SkyWatcher 250P Flextube. He said it was still a large device but the weight he found he could deal with.

He showed us that he had a mounting for two finder scopes, a conventional one and a red dot finder. He also fitted a small double spirit level so that the could easily set the base level he found the drives work better when it is level.

He said that unusually for a dob it was a GoTo he took us through the set up procedure which appears very easy.

He found the handset poor so uses a Wi-Fi device that plugs into the scope and connect to his phone via an app. We saw how this works and amazingly the scope can be moved manually to speed things up without upsetting anything. When he activated the phone´s sky software it showed the location that the scope was directed towards so it was synced. Finding objects was really easy.

Mike said he was announcing some key dates for the coming year so we could get them into our diaries:

Open Nights on 24th March and 15th September. He mentioned that sadly it was poor time for seeing planets.

A Space Day on 28th July this would involve some Rocket launching!

What a full evening.

Wednesday 13th December 2017

Christmas Social and Geminids Meteor Watch

Well we got here at last Ted, Eileen and Mary did us proud. We did our valiant best, but failed as usual to finish the feast.

Large quantities of left over goodies were taken by Mary to give a certain badger and a certain fox that frequent her garden in Rettendon a rather good feast. Hopefully she will ration them or they might burst!

A bunch of our more intrepid members were going off to our Dark Site to hopefully see the Geminid meteor Shower. Mike, Rob, Ed and Peter made up the party.

As we left the church at the end of the evening it was raining but still they headed off!

The following day (14th) - the peak ZHR was due at 02.00 on the 14th Peter emailed around our group the following message. I´m posting it verbatim because it´s so amazing:

So we set off armed with the electronic key to get through the electric security gate about 3 miles from the observing site. Wanting to impress Mike who had not seen the new gate in operation I gave the key fob a series of good pushes from inside the car expecting it instantly slide open. Nothing happened! I got out the car and with mounting frustration got nearer the gate and pushed on the open button with increasing vigour. Still nothing. At this point the meteor watch was nearly cancelled. Ed remembered a message from a rival astronomy group who also had difficulty with the electronic key and who had fiddled with the internal battery and got it working. So in the dark out came the screwdrivers with the conclusion the battery was flat. It was now past midnight and Ed's car lock remote control was the only source of batteries so that also had to be taken to bits. Remarkably with a handful of exposed key circuit board, Ed%acute;s remote control battery and in the pouring rain and wind the gate opened.

We had now reached our destination, but the wind was so intense it was nearly impossible to open the car doors. The rain was travelling sideways and felt like a shot gun blast on any still exposed skin.

We sat in the car with the windows steaming up trawling the internet for a weather forecast that might justify our efforts to venture to such a hostile location. The BBC forecast dangled the carrot of a brief clear slot at 1am so we waited. The rain stopped and the cloud pattern changed, was this a sign? Eventually having drunk most of Ed´s coffee a star became faintly visible, then suddenly there was a flash of a meteor seen through the clouds. That was the signal to abandon the warmth of the car and to risk hypothermia from the gale force cold wind.

A few more stars showed through the thinning cloud so we set up our reclining chairs in the wind shadow of the parked cars and stared into the sky. Gradually the cloud dissipated the wind dropped from a strong gale to a stiff breeze and we began seeing more and more meteors.

Quite quickly the glories of the Winter/Spring sky were on show with a naked eye limiting star magnitude of probably better than 5.5. The Milky Way through Auriga was plain to see.

It looked like we were going to be treated to a good meteor show right at the time of the predicted maximum, so out came my pocket meteor counter ‘clicker’. There were some fast faint meteors, slow bright ones, ones that left a trail and an occasional one that flickered as it crossed the beautiful star filled sky. In total we saw 171 meteors including sporadics. In the hour between 01.15am and 02.15am we saw 150 meteors of which probably 20 were sporadic the other 130 being Geminids. This rate was fantastically high, probably the most intense short period of meteor activity I´ve ever witnessed.

What an adventure!

Wednesdays 20th and 27thDecember 2017 - No meeting - Merry Christmas and a Happy New Year to all our readers!

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