Hi all,
1. Transit of Mercury, 11 November.
The closest planet to the Sun, little rocky Mercury, transits the Sun as seen from Earth much more frequently than its bigger neighbour Venus. On average, there are 13 transits per century. Because it's both smaller and further away from the Earth than Venus, you definitely need optical aid to see it. This transit will begin at 12.35 and end after local sunset, so the Sun will set with the transit still in progress
The transit lasts from 12.35 – 18.04 UT, but the Sun sets before then throughout Ireland.
Local details for Belfast
1st C (when the edge of Mercury first appears to ingress on the Sun) = 12h 35m 18s*,
2nd C (when the whole disc of Mercury first appears totally silhouetted on the Sun) = 12h 36m 58s*.
Mid transit = 15h 20m 57s,
Transit ends = 18h 03m 50s (not vis).
In practice, first contact is essentially invisible, and it's only about halfway through ingress when it becomes readily visible.
First contact will appear at a Position Angle of 110 degrees
The Sun sets at 16h.35m in Dublin, and at 16h 27m in Belfast. The Sun's altitude at mid transit will be 07º 9' at Belfast, and 08º 11' in Dublin.
NB: This will be the most central transit until 2190 Nov 12!
OBSERVING ALTITUDE and DIRECTION
In order for you to plan your observing location to get the best possible view, here are the positions of the Sun at critical stages, and intermediate hourly intervals, for Belfast, and for Portmagee in SW Kerry.
You can interpolate from these to get a fairly accurate indication for your own location. Basically, the further South you are, the higher up the Sun will be at any given stage, and the further West you are, the later the Sun will set, and thus you'll see a bit more of the transit.
BELFAST PORTMAGEE
Alt.º ' Az º Alt.º ' Az.º
1st contact, 12.35 17 44 187 20 43 182
13.00 17 07 193 20 20 189
14.00 14 06 208 17 44 204
15.00 09 13 221 13 00 218
Mid transit, 15.20 07 16 226 11 03 222
16.00 02 57 234 06 39 231
16.50 below horizon 00 34 241
The last transit was on 9 May 2016, and the next one won't be until 2032 Nov 13, with mid transit at 08.55. Sunrise will be at 07.51 in Belfast, so most of that transit will also be visible from here.
This will be the Mercury transit with the longest duration since 1973, and the longest until 2190 Nov 12.
SAFE VIEWING: Like anything involving observing the Sun, eye safety is paramount. You should NEVER look directly at the Sun with any sort of optical instrument, or you will seriously damage your eyes, with possible permanent blindness.
The only safe ways to observe this event are as follows:
1. Telescope or good binoculars which you fit with a specially designed solar filter such as Baader Astrosolar, which you make to fit your own instrument using just scissors, card, and tape. If you are using binoculars you should either make a filter for each objective (front lens), or else make only one, and make sure that the front lens cap is securely fitted over the other objective. Do NOT use just an eyepiece lens cap, as the focused sunlight will quickly burn a hole through it.
Since Mercury is quite small, you'll need fairly high-power binoculars to see it – a pair with a magnification of at least 12x.
2. Projection Method: use either an ordinary telescope, or one half of a good pair of binoculars, to project the image onto a piece of white card held about 20 – 30 cm behind the eyepiece. You'll also need to fit some sort of a screen over the eyepiece end of the telescope tube to prevent direct sunlight falling on the projection screen and spoiling the image. This method has the advantage that a number of people can observe the event simultaneously – all standing with their backs towards the un, looking at the screen. See the photo for how the projection is done.
If you have a telescope
3. A proper Solar Telescope designed for observing the Sun. These are very expensive, and if you already have one, you'll know how to use it.
4. A special solar eyepiece, which you use with an ordinary telescope. These are also very expensive, and if you already have one, you'll know how to use it.
PHOTOGRAPHY: never try and photograph the Sun directly with any sort of camera: you will almost certainly damage the CCD chip. You should either photograph through a telescope fitted with a filter as above, or else photograph the projected image as in 2 above.
Alternatively, if you have a camera with a telephoto or zoom lens which gives a magnification of at least 10 over a standard view you can make a solar filter to fit over the front of the lens as in 1 above. Note that a 'zoom range' of 10 to 1 is not enough, as that's the total range, from wide-angle to medium telephoto; such a lens might only magnify 6 or 7 times above the standard view, which will not be enough.
* For the nerds/purists. My Skymap Pro 11, now about 15 years old, gives those times for first and second contacts for Belfast. But the IAS's "SkyHigh" for 2019 gives times for Dublin of 12h 35m 38s and 12h 37m 10s, and says that times will not differ by more than 2 seconds throughout the rest of the country. That's a difference of 20 seconds between the two predictions, so it would be interesting to see which is closer to what we see.
For reference, the Geocentric 1st & 2nd contact times are 12h 35m 27s and 12h 37m 08s. The horizontal parallax of the Sun will be 08.9"; that of Mercury will be 13.0", a difference of only 04.1", so one's observing location anywhere in Ireland should cause very little difference.
Also, according to Skymap Pro 10, Ingress takes a total of 1m 40s, and according to Fred Espenak it takes 1m 41s, so that's as close as makes no difference. But according to SkyHigh it takes only 1m 32s. That's one aspect that should not vary at all no matter where you are on Earth, so that's odd.
It could be that the times quoted in SkyHigh are geocentric, whereas mine are topocentric, i.e. they allow for the fact that we're at a certain point on the surface of a rotating Earth.
If anyone in Ireland can take high resolution video of ingress, that would be very useful, as you can then run it backwards to see just when 1st contact occurred.
2. Observing events for the Transit of Mercury.
The IAA will have a public observing event at the Divis Mountain Car Park, which is off the Divis road, off the B38.
The car park is at N 54.5992635; W -6.0402635.
We will be observing from the site of the Barn Café, at N. 54.6004593, W -6.0361642. If you have a tel;escope, you can bring your car up to the Barn café site, otherwise park at the car park on the road.
We will be there from about noon, and stay to sunset, or when clouds beat us. If the weatgher looks absolutely hopeless, check our website for updates on whether we'll be there or not.
Blackrock Castle Observatory -Time: 12.30 pm – 4.30 pm. Audience: All welcome! Admission: Free. Further details here: https://www.bco.ie/events/transit-of-mercury-2/
Armagh Observatory will also host an event, see their website for details.
3. IAA Public Lecture, Wednesday November 20, 7.30 p.m. "New Perspectives Big and Small of the Trans-Neptunian Region", by Dr Meg Schwamb, QUB )
Details; 7.30 p.m., Bell Lecture Theatre, Physics Building , QUB. Admission free, including light refreshments. See www.irishastro.org. more details inn next bulletin
4. IAU 100 Astronomy Day in Schools, 10 – 17 November
As one of IAU100's goals is to foster communication and exchange of ideas for the global astronomical community, this also includes the exchange of knowledge and ideas with the next generation of astronomers. The IAU100 has launched the Astronomy Day in Schools Global Project. This initiative hopes to instil some interest and passion for space sciences to continue the momentum of IAU throughout the next 100 years.
Any amateur or professional astronomer is invited to participate by organising astronomy activities in schools taking place around the week 10-17 November 2019, which includes the World Science Day for Peace and Development on 10 November as well as a Mercury transit on 11 November, which offers an exciting outreach opportunity for the visiting astronomers. This project is also a special opportunity for students to directly interact and engage with astronomers in their communities. Organisers of registered events will have the opportunity to win different prizes.
5. Space Careers Roadshow at National University Of Ireland Galway, 22 November. For Science Week 2019 and the Galway Science & Technology Festival , National University of Ireland Galway will host a Space Career Roadshow in conjunction with Science Foundation Ireland, ESERO Ireland and CIT Blackrock Castle Observatory. These roadshows will provide students with an excellent opportunity to engage with space industry professionals, and third level institutions, so that they can get a taste of the exciting opportunities that a STEM career in Space has to offer.
Date: Friday 22nd November 2019, Time: 10 am – 2.15 pm. Audience: Transition Year to Leaving Cert. Admission: Free. Further details here: https://www.bco.ie/events/space-careers-roadshow-at-nuig/
6. Armagh Observatory and Planetarium: Robinson Lecture, "Collisions and Catastrophes" with Stargazing and Dome show "Asteroid: Mission Extreme", 27 November.
6.30pm: Doors Open
7pm Talk: Delivered by Professor Monica Grady, Professor of Planetary and Space Sciences at the Open University. Best known for her work on meteorites and with the ESA Rosetta spacecraft project, the Philae lander and its Ptolemy instrument. Asteroid 4731 was named Monica Grady in her honour.
Talk Title: Collisions and Catastrophes
Monica Grady will explore the hazards of cosmic collisions, and explain why it is important and fascinating to study the material that arrives uninvited on our planet every day.
8pm Dome show: Asteroid Mission Extreme
Stargazing (weather permitting) from 7pm-9pm
7. Mission Santa, Christmas experience, AOP, every Saturday 30 Nov – 22 Dec. For kids, of course. Booking at www.armagh.space
8. INTERESTING WEBLINKS (Disclaimer - Use of material herein from various sources does not imply approval or otherwise of the opinions, political or otherwise, of those sources). NB: If the title in the weblink does not indicate the subject matter, I give a brief simple intro before the link. I may also comment about the link afterwards.
ASTROPHYSICS
Brightest ever x-ray burst from pulsar https://newatlas.com/space/nasa-nicer-brightest-x-ray-burst-pulsar/
https://earthsky.org/space/tess-captures-black-hole-shred-star-video
EXOPLANETS
Views of giant planet in wild orbit would be unparalleled https://www.sciencedaily.com/releases/2019/11/191105075836.htm
IMAGES
https://newatlas.com/space/nasa-tess-exoplanet-hunting-satellite-image/
SPACE
9. JOINING the IRISH ASTRONOMICAL ASSOCIATION. This link downloads a Word document to join the IAA. http://documents.irishastro.org.uk/iaamembership.doc
If you are a UK taxpayer, please tick the 'gift-aid' box, as that enables us to reclaim the standard rate of tax on your subscription, at no cost to you. You can also make a donation via Paypal if you wish: just click on the 'Donate' button. See also www.irishastro.org .
The Irish Astronomical Association is registered with The Charity Commission for Northern Ireland NIC 105858
DISCLAIMER: Any views expressed herein are mine, and do not necessarily represent those of the IAA.
Clear skies,
Terry Moseley
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