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The CHESTERFIELD ASTRONOMICAL SOCIETY

Newsletter APRIL 2017

CAS website: www.chesterfield-as.org.uk Registered Charity No. 514048 Our Facebook page: Our Facebook Page Newsletter Editor: Sue Silver Newsletter: newsletter@chesterfield-as.org.uk

President – Mark Eustace; Secretary – Marilyn Bentley; Treasurer – Graham Leaver.

Committee Members: - Sue Silver, David Frost, John Marsh and Catherine Wood

Subscriptions - full membership £65 or £6.50 per month by Standing Order (10 months) Senior citizens (60 yrs and over) and students (18 yrs and over) £45 or £4.50 per month by Standing Order (10 months) Juniors members - (17 yrs and under) £0. (All juniors must be accompanied by an adult who must be a fully paid up member).

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CAS News OPEN EVENING – SATURDAY 1ST APRIL We are having an open evening at the Observatory on Saturday 1st April starting at 7pm. There will be a series of talks in the lecture room and a tour of the dome. Hopefully, weather permitting, we will be able to use the big telescope together with some other telescopes outside on the patio. There will be refreshments and a raffle. Please come along and enjoy the evening with us. However we must ask you not to park in Hastings Close to avoid congestion but the Eyre Chapel car park (behind the Nag's Head pub) will be open for you. This is FREE for Members (providing you show your membership badge) but visitors/general public the fee is £3 per adult. The Hubble Space Telescope

The Hubble Space Telescope (HST) was launched into low Earth orbit in 1990. Its

successor is the James Webb Space Telescope due for launch next year. What might

surprise you is that the HST could last until 2030 or even 2040.

Putting a telescope into space means that all the problems we have with light pollution

and atmospheric interference go away. That’s why HST has been able to take some of

the most amazing, detailed images of space ever seen.

HST was proposed back in the ‘70s but due to various problems, its launch was delayed

and when it finally got into space it was found that its mirror had been ground

incorrectly. A servicing mission in 1993 corrected this.

HST is the only telescope designed to be serviced in space by astronauts and it has

had five repairs, upgrades and equipment replacement missions to date. There are no

plans for a sixth servicing mission.

The scope’s mirror is 2.4 metres (7.9 feet) in diameter and has four main instruments

that observe in near ultraviolet, visible and near infrared light. The results are not just

the most stunning space images ever but also some breakthroughs in astrophysics.

Here are some of the important discoveries made by the HST:

A significant improvement in the accuracy of the Hubble constant; a key number used in

calculating the rate of expansion of the universe. The accuracy has gone from +/- 50%

to +/- 10% which is consistent with other measurements made independently by more

sophisticated equipment developed after Hubble’s deployment. To put this into

perspective, before Hubble, the estimated age of the universe was 10 to 20 billion years

old but now we have it down to 13.8 billion years old thanks to the HST.

Hubble observed that the universe is increasing in its rate of expansion and that’s why

scientists are now trying to explain dark energy.

The HST has confirmed the existence of black holes at the centre of many galaxies and

led scientist to note that the size of a galaxy and the mass of its central black hole are

connected.

Hubble captured images of comet Shoemaker-Levy crashing into Jupiter; a type of

event that happens only once every few centuries.

The Hubble Space Telescope has given us a unique and fascinating insight into the

universe and enthralled us with some of the most wonderful images of solar and deep

space objects ever produced. If you would like to see them, pop over to these sites:

www.nasa.gov/hubble

hubblesite.org/

www.spacetelescope.org

You might also be interested in HST’s Wiki entry (on which this article is based) found

here:

https://en.wikipedia.org/wiki/Hubble_Space_Telescope

When the James Webb Space Telescope comes on line it will have a mirror three times

the size of Hubble’s. I’m sure we are going to be dazzled with even better images and

surprised as it discovers many more mysteries for scientist to explore and (hopefully!)

explain.

Cheers,

Mark.

Coming up.......... Friday 7th April – A talk by James Mullaney - The Future of the Universe Haddon Grove Asto Camp - 21st – 23rd April As you all probably know the Astro-camp which was supposed to take place on the weekend of 17th - 10th March was cancelled. This was due to the weather forecast saying that the tail end of storm Stella was coming from the USA and was going to bring rain and gale force winds over the weekend, not a good mix for camping. The re-scheduled date is Fri 21st April - Sun 23rd April and will take place at our normal campsite, Haddon Grove. The weekend will be open to members and friends of the Society to camp or to just visit us on Fri / Sat night. All I ask is that anybody who wishes come camping, caravaning with electric hook up or just visiting if they could let me know so that I can let the owner of the campsite know the numbers who will be going. My contact details are 07806670609 peterdavison45@virginmedia.com .

AGM – FRIDAY 7TH MAY 2017

The AGM is on the 5th May at 7pm. This is for Members to vote for Chairman, Secretary and Treasurer and committee members. Please pass any items/proposals to Marilyn Bentley you may have for the Agenda by 4th April. This will start an hour before our usual opening time.

Photo Gallery...........................

Venus – from Graham Leaver taken Wednesday 8th March Also from Graham the Moon Monday 6th March......

Clavius Tycho Tycho

Plato Alpine Valley

Rupes Recta – Straight Wall Thanks for these Graham.

These on 8th March .........

Gassendi Clavius

Gassendi

Copernicus "...attached the best of the first four I took which has been a bit over cooked but it shows the transit of Io's shadow, Io was also transiting but you can't see that, and the GRS was appearing in the lower half. Better result than I had expected given the conditions....". This was taken by Graham 12/03/17

These also from Graham 20/03/17

"....Jupiter's elevation is getting higher and the seeing was better but not brilliant but at least some detail coming through. The GRS moving off the disc. Other Jupiter photographers would be using barlows/powermates but I can't get the image quality if I do that so my efr and image size is smaller.....". Come on all you astrophotographers give Graham some competition!!!!! Things to see in April.................. Saturday 1st Mercury reaches greatest eastern elongation and is visible in the west approximately forty minutes after sunset. Monday 3rd The lighting effect that creates the so called 'Lunar X' can be seen this evening from 22:20 BST onwards. Tuesday 4th Io and Ganymede are eclipsed by Jupiter's shadow at 01:40 and 05:38 BST respectively. Io can also be seen coming out of occultation from behind Jupiter's disc after the eclipse at 03:57 BST. Thursday 6th Comet 41P/Tuttle-Giacobini-Kresek is predicted to be at its peak brightness tonight approximately mag. +6.6. This places it within easy binocular range. Friday 7th Jupiter reaches opposition tonight and presents two moon events. Callisto passes just north of Jupiter's northern limb during the early

hours and Ganymede transits Jupiter's disc while perfectly lines up with its own shadow between 19:30 and 21:55 BST. Monday 10th The virtually full Moon appears 1.5° to the north of mag. -2.3 Jupiter. The bright planet will easily hold its own against the Moon's formidable glare. Friday 14th Ganymede and its shadow transit Jupiter with the moon passing onto the disc at 22:57 followed by its shadow at 22:30 BST. The transit ends at 01:01, the shadow exiting the disc at 01:52 BST. Thursday 20th Mag. +1.6 Mars is 3.6° south of the Pleiades open cluster this evening. This morning's Moon shows a favourable libration for the western limb. Saturday 22nd Tonight is the peak of the April Lyrid meteor shower. Expect up to twenty meteors per hour. Sunday 23rd Look out for the 14% lit waning crescent Moon and mag. -4.4 Venus rising in the east from around 05:00 BST. Friday 28th From 21:30 look for the 8% lit waxing crescent Moon near Aldebaran with Mars 9° to the right and the Pleiades 6° right of Mars. Sunday 30th Venus is at its brightest, shining in the eastern morning pre-dawn sky at mag. -4.4. Things to remember......... Amazon..................... Please remember if you are ordering anything from Amazon follow the link on our website – this earns us commission!!! Thank you. Also Please check out our Facebook page by following the link below: Our Facebook Page

ASTROSTUFF Hubble solves the mystery bulge at the center of the Milky Way Our supermassive black hole has been on a diet for millions of years… but when did it last splurge?

By Alison Klesman | Published: Thursday, March 09, 2017

The Fermi Bubbles are two huge structures “burped out” by the Milky Way’s supermassive black hole and visible in X-ray and gamma-ray light.

NASA's Goddard Space Flight Center

The Milky Way appears as a relatively flat structure when viewed along its plane in visible light. Gamma-ray emission, however, paints a different picture: two huge structures billowing outward from the galaxy’s bulge like an enormous hourglass. Named the Fermi Bubbles, these structures are the result of the Milky Way’s supermassive black hole gorging itself on interstellar gas in the past. Using the Hubble Space Telescope (HST), astronomers have now determined just when these structured formed.

A team of astronomers led by Rongmon Bordoloi of the Massachusetts Institute of Technology has used distant quasars to trace the structure and motion of the northern Fermi Bubble, which rises 23,000 light-years above the plane of the Milky Way and contains enough cool gas to create 2 million Sun-size stars. By observing the ultraviolet light from 46 quasars with the Cosmic Origins Spectrograph (COS) on HST (and adding one quasar observation with HST’s Space Telescope Imaging Spectrograph), the team mapped out the motions of cool gas within the bubble to pin down its age: 6 to 9 million years. Most galaxies contain a supermassive black hole at the center, and our Milky Way is no exception. Sgr A* resides in the Milky Way’s bulge and has a mass equivalent to 4.5 million solar masses. Today, Sgr A* is relatively quiet, accreting slowly as the galaxy ages. By contrast, quasars are young, massive supermassive black holes at the centers of galaxies in the early universe, sucking down huge amounts of gas and dust that shine brightly as the material is funneled into an accretion disk before finally passing into the black hole. Like these younger black holes, astronomers believe that our own supermassive black hole was once more active, at a time when the galaxy was still forming and material was more plentiful for accretion. Sometimes, though, material doesn’t actually make it all the way into the black hole. Matter can escape along the black hole’s spin axis, exiting the area — and often the galaxy altogether — as huge outflows that span tens or hundreds of thousands of light-years. The Milky Way’s Fermi Bubbles are such an outflow; they were discovered in 2015 and named after NASA’s Fermi Gamma-Ray Telescope, which spotted them. Learning more about the origins of these outflows requires information about their motion. “We have traced the outflows of other galaxies, but we have never been able to actually map the motion of the gas,” said Bordoloi in a press release announcing his group’s results. The

work also appeared in the January 10, 2017 edition of The Astrophysical Journal. “The only reason we could do it here is because we are inside the Milky Way. This vantage point gives us a front-row seat to map out the kinematic structure of the Milky Way outflow.” As the quasars’ light travels through the bubble to reach Earth, it highlights the gas in bubble itself, allowing astronomers to determine information such as its chemical composition, temperature, and motion. The “cool” gas in the northern Fermi Bubble, which contains elements such as silicon and carbon, was clocked at 2 million miles per hour (3 million kph) an reaches temperatures of 17,700 degrees Fahrenheit (9,800 degrees Celsius). Such cool gas is actually likely gas from the disk of the galaxy that has been swept up by and integrated into the outflow itself, which has temperatures of up to 18 million degrees F (nearly 10 million degrees C). It is these high temperatures that cause the gas to shine in energetic light, such as gamma rays. Once the gas’ motion — its direction of movement and velocity — was measured, astronomers used this data to turn back the clock and pinpoint when the gas started moving. This origin is also the last known “big meal” enjoyed by Sgr A*, which hasn’t managed to suck down such a significant amount of matter ever since. “What we find is that a very strong, energetic event happened 6 million to 9 million years ago,” Bordoloi explained. “It may have been a cloud of gas flowing into the black hole, which fired off jets of matter, forming the twin lobes of hot gas seen in X-ray and gamma-ray observations. Ever since then, the black hole has just been eating snacks.”

FUN STUFF Teacher: "Kids, what does the chicken give you?" Student: "Meat!" Teacher: "Very good! Now what does the pig give you?" Student: "Bacon!" Teacher: "Great! And what does the fat cow give you?" Student: "Homework!" Q: What is the difference between a cat and a comma? A: One has claws at the end of its paws and the other is a pause at the end of a clause.

Wife: "In my dream, I saw you in a jewelry store and you bought me a diamond ring." Husband: "I had the same dream and I saw your dad paying the bill." That’s all folks.

Sue This newsletter is sent out to all present members without whom the Society could not survive. Also to previous members and people with an interest in astronomy in the hope that they may wish to join/re-join the Society. If you no longer wish to receive this newsletter by e-mail please let us know. Thank you.