Worthing Astronomers April 2015 by Brian Halls

The Southern Astronomer No.79 â&#x20AC;&#x201C; April 2015

SOUTHERN ASTRONOMER THE

MONTHLY MAGAZINE OF WORTHING ASTRONOMERS & WORTHING SKYWATCHERS

Above: Members of WA, Worthing Skywatchers and members of the public watch the skies for the partially eclipsed Sun. Left, a bird takes flight during partial and below, totality as seen on the eclipse track.

The Southern Astronomer No.79 – April 2015

Astronomy Meetings The groups listed below begin their meetings at 19.30hrs BST Worthing Astronomers (WA) meet on the first Friday of the month, every two months (February, April, June, August, October and December) at Goring URC, corner of Shaftesbury Avenue and Barrington Road, Worthing, BN12 4EA. Admission £3. This month only it is the SECOND Friday of April. Adur AS (AAS) meet at Southwick Christian Community Church, 1-5 Roman Crescent, Southwick BN42 4TY, first Monday of the month. Admission: £5 for guests, £3 for members. Note change to date this month only WA and AAS venues have off road parking facilities and grounds adjacent for setting up telescopes when conditions allow. WA members will be made welcome at the above groups. More monthly details in the Quick View Diary, page two. Worthing Astronomers is a free to join society with a membership of around 380 persons, all sharing an interest of Astronomy. With the aid of this newsletter, website, social media, regular star parties, workshops and public observing events we hope to encourage and share our interests in observing the sky with the public, our colleagues in our own group and with neighbouring societies.

This Issue Diary, listings and information Sompting Primary School – Observing Night Preview: April Workshop – telescope Clinic Partial Eclipse Report Observing Notes: April

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QUICK VIEW ASTRO EVENTS DIARY

April

All times shown are Universal Time (UT = GMT = BST minus 1 hour) For WA and AAS details, see side bar on left

1 4 10 12 13 17 18 24 25 26 29 30

Sunrise 0540h : Sunset 1835h Global Astronomy Month starts Full Moon (03h); lunar eclipse, not visible from UK WA: Workshop Night – Telescope Clinic Moon: Last Quarter (03h) GAM: Sun Day AAS: Lunacy! Our Nearest Neighbour-The Moon by Robin Durant Moon at perigee (03h) New Moon (19h) GAM: Moonwatch – Moon & Planet Observing from Worthing Seafront Moon: First Quarter (23h) - – Moon & Planet Observing from Worthing Seafront Jupiter 5.3°N of Moon (15h) Moon at apogee (04h) Sunrise 0439h : Sunset 1922h Global Astronomy Month ends

CONTRIBUTIONS AND UNSUBSCRIBE Contributions – written articles (preferably word processed in .txt, .doc or .odt format), photographs or letters to the editor for the April issue should be in by April 15 and sent to the editor at the contact address: editor@worthingastronomers.org.uk If you no longer wish to subscribe to the group and cancel newsletters and other information, please send an email to: info@worthingastronomers.org.uk with 'Unsubscribe' in the subject line; we do not want our stuff to end up like spam littering your in-box. Volunteers are always welcome: if you want to find out more, call 01903 521205 or drop us a line at the e-mail address above. If you like the newsletter or its content please feel free to distribute it to anyone you know who might be interested. Content is subject to copyright to the group and/or the individuals whose images or articles are used.

Cover picture credits: Top – Gary Isherwood Left – Stuart Hillaker Lower right – David Storey

Lunar phases April 2015

WORTHING ASTRONOMERS, PUBLIC LIABILITY INSURANCE & THE FEDERATION A thank you to those who have already made donations to the group for the PLI. It costs £164 a year but is something we need to allow us to meet and do public outreach events. You will note the PLI is higher this year. We used to get this via the Federation of Astronomical Societies. Our annual FAS renewal package including PLI would have cost the better part of £60 this year (FAS 'costs' having increased). With just three newsletters and a Handbook (for group administrators – nothing of astronomical interest, apart from a warning that PLI from any other source than the FAS would cost in the region of £1000(!)) it was felt that we were not really getting much for our money, either as a group or for grass roots members, so we decided to source the PLI by other means which we have and drop the FAS where incidentally, we were one of the larger groups. The new insurer has advised quite clearly what the insurance covers – something the FAS have always been hazy about when questioned about their insurance coverage. In all the years we were a FAS member, not once did we receive clear information as to what the insurance actually covered – or not. Please keep the donations coming in. Many thanks.

The Southern Astronomer No.79 – April 2015

SOMPTING COMMUNITY PRIMARY SCHOOL STARGAZING EVENING March 4

orthing Astronomers were invited to give the children who attend Sompting Community Primary School in Sompting village, views of the night sky. The evening proved to be clear and not too cold and nine members with optical equipment along with other members who supported the event turned up. Andy Lee gave a rolling series of short presentations (lower picture) on the subject of eclipses for the children and their parents before they went out onto the south facing school field and looked through the telescopes. The Moon was rising full in the east but was still able to show its mysteries to all those who looked while a bright Venus and a fainter Uranus were in the west, and Jupiter with its retinue of satellites was high in the south east. Steve Bassett who organised the evening writes: A big thank you to all who came along [on the] night and gave up their time to help out. We had a great evening with Andy's talk going down very well and the 9 scopes we had out on the playground and Christine's [Jones] binocular sessions were all very well received. Richard the head teacher was very impressed with us and is looking forward to doing the same next year. Here are just a few hurriedly shot pictures from the evening taken when we had a gap between the crowds.

The school playground makes for an ideal observing area

Steve advises that about 200 children and parents shared the excitement of looking through telescopes during the evening. Many thanks to those members who bought their telescopes with them and were willing to share views of the sky with all those who attended. Special mention should be made about Christine Jones' collection of binoculars – some dozen or so which were loaned out to anyone who wanted to have a look through them. Many thanks Christine. Thanks also to Andy Lee for stepping in at very much short notice, as last minute work commitments caused problems for the original speaker.

Andy Lee demonstrates how and why eclipses occur

All pictures © Steve Bassett

A thank you to Steve for his work in setting up this event with the school and of course the head teacher and school staff who made us all so welcome.

APRIL WORKSHOP EVENING – TELESCOPE CLINIC April 10

a few things that you may want to learn more about. Or just pop along for a chat and mingle.

The Worthing Astronomers April Workshop Telescope Clinic may just be for you.

With imaging devices on many portable electronic goods, many members are wanting to find out how to take those kind of images they see on our Facebook and Flickr pages on the web and in this newsletter.

ot a telescope and not too sure on how to use it. Got a technical issue with your telescope/ binoculars or any other piece of equipment. Looking to update instrumentation and looking for ideas. What telescope do you need?

This spring meeting of the group is a useful one as regular telescope users will be on hand to help out those who are trying to get to grips with using their equipment. Accessories - are they needed? Eyepieces – what types? Focusers, cameras, filters? A list of quite

How do you capture a picture of the Sun or get a coloured image of Jupiter or a deep sky object? Help will be at hand as will cups of tea/coffee and other refreshments. Members will have their own equipment at hand to show. An earlier Workshop proved very successful with members learning

more about their equipment and going out to purchase add-ons. It is also a great chance for us to meet up socially as well. Hope to see you on April 10. Details page 2.

The Southern Astronomer No.79 – April 2015

PARTIAL SOLAR ECLIPSE REPORT Brian Halls

fter months of waiting the morning of the partial eclipse finally arrived – to slate grey cloud in the Worthing area.

pronounced especially around the time of maximum phase.

This did not however stop an intrepid team of observers attempting to capture the event and their perseverance paid off. Be they in groups or acting singly, members produced a selection of, considering the conditions, stunning images. A team met down on Worthing seafront early. Though this was not technically a public observing event, members of the public popped along to join our colleagues (top picture, cover page).

Mike gives the thumbs up to his image of the eclipsed Sun on the view screen of his camera © Mike Williams

Others however bravely took themselves to the far north and onto the track of totality – where the Sun would appear totally eclipsed.

How many of us saw the eclipse © Jan Halls

Linda and David Storey went to the far North to see if they could capture the full eclipse. David's picture (below) shows the fine inner corona.

Though no one in the Worthing area caught the entire eclipse from first contact to last, the break up of the clouds did help everyone at some point..

L to R, Steve Bassett, Chris Pennells and Andy Li © Gary Isherwood

Their patience was rewarded when after maximum, phase, the clouds began to thin out and everyone got to see the silhouette of the Moon across the face of the Sun.

Second Contact © David Storey

David advises that this picture and another (cover) were taken at -22°C ! The picture on this page shows the dying effect of Baily's Beads – the effect of sunlight showing through gaps between mountains which are on the edge of the Moon as the Moon covers the Sun. The red clouds are prominences seen in the solar chromosphere while the milky cloud around the eclipse is the inner corona. Detail can be seen in the corona – the effects of powerful magnetic fields.

It was at this time many members caught sight of the Sun and were able to photograph it or, just view it through their solar filters. At our own home, eight members, friends, family and guests hoped to watch the partial eclipse. Though the observatory and telescopes were set up for viewing the eclipse, they were not required as glimpses of the eclipsed Sun were short lived. We were able however to monitor the BBC special broadcast which showed how the eclipse was getting on throughout the UK and on the totality track. Graham and Mike Williams had decided that the weather forecast for Worthing and the south-east of England was too iffy and decided to head westwards to observe the eclipse. Driving most of the night they found themselves on the north Devon coast at Appledore at about 04.30hrs. Setting up on the seafront and watching the Sun rise, they had better conditions than further east. Mike wrote on the Skywatchers Facebook page: “...cold here on the north coast of Devon, though pub opposite will be getting a visit later.” He later wrote that it would all be worth doing again.

A thank you to all those many members who sent in their fine images of their views of the eclipse – too many to show and note. A brief selection is on the website and a wider selection can be seen on the Skywatchers Facebook page. This event certainly raised an interest in the public and media alike and pictures have been One of the ideas put forward for members to do if disseminated on request to a number of local and there was a chance of too much cloud was to use a regional media outlets for future use. camera to photograph the changes in light levels through the eclipse phase. Despite the perversity of the weather – the Thursday morning was bright sunshine as it was on the Two members did attempt this – I did, using Saturday morning (as it was the following Friday!) – images of the back garden, while James West also it was really a great, fun way to share an attempted the experiment but from Trafalgar astronomical event with friends and colleagues, Square in London. Both of us had some moderate and let us not forget that is what amateur success with the fall of light levels being very astronomy is all about. The eclipse close to maximum phase - Ferring © Lisa Cox

The Southern Astronomer No.79 – April 2015

OBSERVING NOTES April All times are expressed as Universal (UT) and can be considered the same as GMT (BST minus 1 hour). Information, unless otherwise stated is for the 15th of the month After the solar eclipse at the equinox, the Moon is eclipsed on the 4th but as this event occurs during UK daytime, it will not be visible from the UK. We need to wait until the end of September to see our next total lunar eclipse – the first for some years. The lightness of the evenings is drawing out yet the night skies in spring can still be enjoyed, with or without optical assistance. With the Moon close to new during the mid-month. now is a good time of deep-sky objects and meteors.

Visibility of the planets mid-April

Despite an increase in sunspot activity over the last month or two, activity dropped considerably during March – a bizarre situation when the Sun has just passed maximum and should be very spotty. Sunspots have been present but the groups have been comprised of many small and fine sunspots rather than larger spots. A fine spot did appear at the end of the first week – AR 2297.

Sunrise, set and twilight times mid-April

TRANSIT OF MERCURY May 9, 2016 After the excitement of waiting for the deep partial eclipse, have you got a taster for observing the Sun (safely of course)? The next 'thing' solar related will be the transit of Mercury in May next year. Transits of Mercury are not as rare as transits of Venus - they occur over a hundred years apart – the last set were in 2004 and 2012 – the next won't be until 2117 and 2125. We don't have that problem with Mercury. Due to orbital geometry, Mercury transits across the face of the Sun occur in either May or November – the May transits are rarer occurring at intervals of 13 and 33 years while November transits occur at 7, 13 and 33 year intervals. The last May transit was 2003 – after 2016, the next will be in 2049! The next three transits after 2016 will be November ones in 2019 (11th), 2032 (13th) and 2039 (7th). Portions if not the entirety of all these transits will be visible from the UK. For observers in the UK and much of western Europe, the whole of the 2016 transit will be visible from late morning (using Universal Time) to sunset. May 9 is a Monday so a chance for the lucky some to perhaps have another long weekend.

Active Region 2297, March 7

Mercury transit data, 2016

It crossed the Sun over the following two weeks or so, before disappearing prior to the partial eclipse on the 20th. There was only a small sunspot visible through the eclipse – and many were lucky to compare the apparent blackness of the sunspot with the true blackness of the silhouette of the Moon.

There will be a bit of a build up to the transit – possibly a National Astronomy Week event – but of course more details nearer the time.

The Southern Astronomer No.79 – April 2015 Observing Notes Continued

The Moon is full at the beginning of the first week of the month. Traditionally this is considered to be a bad time for the newcomer to astronomy to look at the Moon and find ones way around it. This is due to full Sun falling on the lunar surface, thus eliminating shadows that cast features into relief. However, using a low power (say x30) on a telescope or even using a low power device like a pair of binoculars, there are things that can be seen. Though many lunar features that appear on maps and charts are not easily recognisable, others are. The beginning of the month may be a good time to have a look at the Moon and see some of the bright features that are subdued at other times during the lunation (the period of time from one new Moon to the next). The most obvious is the bright ray system. To the south is the ray crater, Tycho. Its ray system is 'splattered' across much of the southern highland portion of our satellite. Interestingly, the rays themselves do not go back to Tycho directly as the crater has a dark ring of material surrounding it as in the picture on the right. This ring is not obvious under high magnification but is more prominent with a low power. prominent object in the evening sky. Heading north from Tycho is the bright ray crater Copernicus while to the west of it is the smaller Kepler. The ray features around these The best time to look at Venus is well before dark. Those with GoTo last two craters are enhanced as they are scattered across the mounted telescopes or accurately polar aligned equatorial darker background of the mare (comprising basaltic (lava) material). telescopes will be able to find it in daylight, though I have always found it best to scan for Venus when the Sun has dipped below my It is recognised that these ray craters are some of the younger local horizon or the roof tops to the west of me so it is out of view features on the Moon – they are fairly pristine – that is, they have not and there is no accidental danger of stray sunlight catching my eye. been damaged by later asteroid impacts and the ray material is bright indicating that they too have not been eroded by later With the sky still light Venus is not so dazzling but the use of yellow impacts. eyepiece filter (traditionally a W15) may be a help. Use of light blue filters (W80 for example) are also considered useful. There are many other ray features – most are smaller and the spread of their rays is less dramatic. Over to the eastern part of the No matter how you observe the planet, it will appear at 73% Moon – the part we see as a crescent in the evening twilight – is the illuminated and its angular diameter will be half that of Jupiter – conspicuous enclosed mare, the Mare Crisium. about 15-arc seconds. With good seeing and good optics it may just be possible to make out dusky shadings on the clouds that surround On the western border of the mare, and just visible in the the planet. photograph is a bright crater called Proclus. The crater has a high brightness or albedo. Though it does have a ray system it is the crater itself that is outstanding under high sun illumination. To the north-west of Copernicus (more or less at 'ten o'clock' when looking at the face of the Moon) is another bright crater, Aristarchus. So bright is this crater it can be seen when the Moon is a thin crescent in the evening sky and the night side of the Moon is bathed in earthshine. The astronomer William Herschel even suspected (wrongly) this lunar feature to be an active volcano so bright was it when seen under the above type conditions. The Moon is new on the evening of the 18th – a couple of days later it will appear begin to appear as a thin crescent. As twilight darkness creeps in, the faint ruddy glow of the earthshine will become obvious. Try looking at the Moon during this time for Aristarchus – a low power on a telescope or even a pair of binoculars, are ideal for this. See if you can observe Herschels' 'active' volcano. THE PLANETS

Mercury is poorly placed for much of the month – rising with the Sun at the beginning of the month and sets an hour after the Sun at the end of the month. The other inner planet, Venus is now a

Atmospheric turbulence can be a problem (see above picture) when the planet is close to the horizon. Venus shines at -4.1m and sets at 22.47UT mid- month.

The Southern Astronomer No.79 – April 2015

Observing Notes Continued

As Venus shines bright in the western sky so Jupiter is prominent in the high southern sky at the start of the evening. The 'dance' of its satellites as they swap position night after night as they orbit the planet is fascinating to follow – something one can do with a good pair of binoculars or even a small telescope. The Great Red Spot (GRS) has been observed slowly shrinking over the last year or two but it is still visible. Transit times for April are below (given in US date format): 04/01/2015 @ 19:59 UT 04/03/2015 @ 21:37 UT 04/05/2015 @ 23:16 UT 04/06/2015 @ 19:07 UT 04/08/2015 @ 20:46 UT 04/10/2015 @ 22:24 UT 04/13/2015 @ 19:54 UT 04/15/2015 @ 21:33 UT 04/16/2015 @ 17:25 UT

04/17/2015 @ 23:12 UT 04/18/2015 @ 19:03 UT 04/20/2015 @ 20:42 UT 04/22/2015 @ 22:21 UT 04/23/2015 @ 18:13 UT 04/25/2015 @ 19:51 UT 04/27/2015 @ 21:30 UT 04/29/2015 @ 23:09 UT 04/30/2015 @ 19:01 UT

The Lyrid's

Present thinking is that the Lyrid's in 2015 may give quite a show. If you would like to give meteor observing a go then the BAA Meteor Section has some tips to help - https://britastro.org/node/4944 and for group observing – https://britastro.org/node/4943.

The planet Saturn with its majestic ring system is still an object for the observer planning to stay up late. At the beginning of April it rises at 23.13UT and by the end of the month, 21.11UT. It comes to opposition (due south at midnight) in the latter part of May. The closest Earth and Saturn came to each other was in early February.

The maximum for this shower is expected at 23.00UT on the night of the 22nd (or at 0hrs BST 23rd). Normally we can expect an hourly average of 10. If you plan to image meteors and are successful please feel free to send them in and if possible submit them to the BAA Meteor Section – also note your location and time (in UT) with the image.

The main problem with Saturn is that it is never going to be higher than about 20° or so above the horizon at the moment, so a good skyline is going to be an advantage.

A minor meteor shower which comes to maximum earlier in the month is The Virginids. This is a generic name for a number of small meteor showers whose radiants (the point in space where the meteors appear to come from) are in the constellation of Virgo.

Though the disk of the planet shows a cloud belt system similar to that of Jupiter it is the detail of the ring system that is also impressive.

These showers start in mid-January and are visible until about May though the peak radiant is on the 11/12 April. They produce only about one or two meteors an hour. Comet C/2014 Q2 (Lovejoy) now at about 7m is still gracing our skies. It lies between Cepheus and Cassiopeia mid-month, a green 'smudge' in binoculars or telescope. No other comets are brighter than 10m. STELLAR AND DEEP SKY On a moonless night, if your skies are dark look south and have a quick glance at the sky below Jupiter. It is relatively devoid of stars yet the largest constellation occupies this area of sky – Hydra, The Water Snake.

M88 (Southern Pinwheel Galaxy) is in Hydra though too far south for easy observing; a clear southern horizon is ideal as the object © Cokeham Observatory just pops above the horizon around 0hrs UT for a brief time. A COMETS & METEORS challenge for any of our members to try and observe and even take an image of! The April Lyrids are the major meteor shower for the month. The shower period is between the 16-25 April with the peak on the Slightly easier and visible just west of the meridian at dusk is the 22/23 April. The lack of interfering moon light is an advantage plus open cluster M48 laying close to Hydra's border with the the fact that the expected shower is likely to be slightly better than constellation of Monoceros, The Unicorn. From a dark sky location usual. the cluster is described in being triangular in shape and at about 30arc minutes wide, it is the approximate size of the full Moon. On The shower is associated with a comet we now call C/1861 G1 the eastern side of Hydra also visible low in the south at dusk is Thatcher and previous Lyrid showers have been quite dramatic planetary nebula NGC 3242. This object is quite fascinating as in a with reports of “..starry meteors seemed to fall from every point in small telescope it looks a little like the planet Jupiter – indeed, the heavens..” The Lyrid's can produce bright fireball like meteors Ghost of Jupiter is another common name for it. and in 1992 produced an hourly average of 90 meteors.

The Southern Astronomer No.79 â&#x20AC;&#x201C; April 2015

The Night Sky from the Worthing area at around 21.30UT, April 15

Stellar & Deep Sky continued

Lying 1400 light years from us it has a green hue about it and with larger instruments the shell of the nebula can be seen. An alternate name is The Eye Nebula.

NGC 3242 as seen in a small telescope

What we are observing is the expanding shell of matter from a star that went supernova nearly two thousand years ago. The constellation first appears in Babylonian folk lore and was a serpent to them as well. The Greeks must have later adopted/adapted it for their legends; the Hydra was the creature killed by Hercules as one of his Labours.