As we’re now well into the second half of summer in the Northern hemisphere and the number of hours available to us for stargazing are slowly but surely increasing again, the mild evenings make for some very comfortable viewings of some very special wonders in our night sky. So pull Read more
We completed a half orbit around the Sun since I wrote the November Night Sky. It felt like yesterday, but it has been 6 months ago. The time is cruel… The days are already quite a bit longer and are still getting longer. Stargazing is getting more difficult in this Read more
Author Name: Thomas Howarth What you’ll discover in this blog post: What may happen if a star wanders too close to the Solar System How astronomers look for these incoming stars How astronomers of the Armagh Observatory and Planetarium used the ESO’s VLT to rule out one such close encounter Read more
So, party season is over and we’re looking towards a long, cold January before the weather starts to heat up again. However, January is a great time to go stargazing as the nights are long and we can start our lookout in the late afternoon. Not to mention that the Read more
The story of Jocelyn Bell Burnell’s discovery of pulsars is one of the best known in astronomy. The story of how, as a graduate student at the University of Cambridge, she detected “a bit of scruff” on the chart recorder of the radio telescope designed by her supervisor Anthony Hewish. Read more
So the nights are drawing in and in as we get closer to the festive season, and though Christmas might not be quite the same as usual this year, there’s still plenty to celebrate. One great socially distanced activity you can do is stargazing! It’s outdoors and doesn’t require a group, and so you can easily go out and have a wee look up at the stars – just make sure to wrap up warm at this time of year!
By Prof. Simon Jeffery Enter the name ‘PHL 417’ in the public database which tells you nearly everything known about nearly every star in the sky, and you will find an almost blank entry. It is enigmatically identified as a ‘Blue object’ of the 17th magnitude, or about 200,000 times fainter than the faintest stars visible to the naked eye. It has no other names, and no scientific Read more
In a new paper, Simon Jeffery reports the discovery of standing waves on two small hot stars similar to the pattern of jet streams seen in the Earth’s atmosphere.
By Simon Jeffery, AOP Research Astronomer In 1930, Dorrit Hoffleit reported that star number #4749 in the Harvard List of variables had faded four times between 1897 and 1929, and identified it as an R Coronae Borealis (RCB) variable. RCB stars are luminous low-mass stars (red giants) with surfaces around Read more
Moving on to our February Night Sky article (already) featuring htings to look out for while the sun still sets nice and early. Watch out for the cold, though!
Lying somewhere between young main-sequence stars and old white dwarfs, hot subdwarfs are blue stars with about half the mass, a tenth the diameter and ten times the brightness of the Sun.
Summer’s here! The weather’s heating up and skies will hopefully be clear for a bit of stargazing! There are lots of interesting sights in the sky this July, so while you may have to wait longer for it to get dark, get outside, allow your eyes to adjust and get Read more
This week’s instalment of the Technical Applications of Astronomy to Society features a piece written by Professor Antonio Mario Magalhaes; astronomer, IAU member and Full Professor at the Instituto de Astronomia, Geofisica e Ciencias Atmosfericas of the University of São Paulo in Brazil. In this piece, he outlines the wider Read more
Article by: Gavin Ramsay Unlike our Sun, around half of all stars have another stellar companion. The closest stars to the Sun are two bright southern stars, alpha Centauri A and B, which orbit each other every 80 years and Proxima Centauri which orbits A and B every few tens Read more
The long cold dark nights have well and truly settled in, and now that it’s December it’s officially acceptable to say the C word. Christmas, Christmas is coming! And so is Santa Claus! Decorations are going up, there’s mad panic to buy Christmas presents and families are organising who’s having dinner and where. Ahh I love this time of year.
NASA has announced the retirement of the Kepler spacecraft. After launch in March 2009, it began a continuous observation of a 115 square degree field of view (the diameter of the moon is 1/2 a degree) between the constellations Cygnus and Lyra.
October is here! It is one of our favourite months as there is so much more to see in the sky and the nights are getting deliciously darker. One thing to remember when you are stargazing is to wrap up warm when you venture outside. The nights are getting much colder, and with some of the best stargazing occurring in the early hours of the morning, we don’t want anyone catching a chill. Thermals and a thermos filled with hot chocolate or coffee will do the trick. Also don’t forget that we will be starting our Star Tracker evenings in the coming months!
Have you ever been worried about the impact of an asteroid wiping out human life? Well, I have some disturbing news for you: there is another possibility involving the explosion of a massive star that gives rise to a gamma-ray burst (called by astronomers simply a GRB), when the star ends its life producing a black hole.
September 2018 will see over 50 astronomers from around the world gather at the Armagh Observatory and Planetarium to discuss the latest news about hydrogen-deficient stars. These stars have lost nearly all the hydrogen from which they were made, to leave only nuclear ash. Astronomers want to learn how these rare and short-lived remnants formed, and what drives their spectacular changes in brightness.
July 4, 2018 saw the 150th birthday of Henrietta Swan Leavitt (1868 – 1921), one of the most important astronomers of the 20th century. Born in Lancaster, Massachusetts, Leavitt graduated from Radfcliffe College, Harvard, in 1892. She then stayed on at the Harvard College Observatory as a volunteer research assistant. Whilst attempting a graduate degree in astronomy and travelling in Europe, she became ill with grave consequences for her hearing. In 1902, then director, Edward Pickering, invited Henrietta to join the permanent staff at Harvard, where she was assigned to study “variable” stars.
The Armagh Observatory and Planetarium are holding a special event to mark the lunar eclipse, coming at almost the same time as the opposition of Mars. The event has proved so popular that tickets sold out within a couple of hours of being released, so we have written this blog entry to tell you about what will happen if you missed out on obtaining a ticket or are going to try to observe the eclipse from elsewhere.
Approximately every other star in the Milky Way galaxy is in a ‘binary’ system. These binaries are made up of two stars orbiting around a common centre of gravity. The time taken for the stars in the binary to make one revolution is called the ‘orbital period’. Binaries have a wide range of orbital period. The closest stellar system to the Sun is alpha Centauri which has two stars not unlike our Sun orbiting around one another every 80 years. A third member of the system, Proxima Centauri, which is much smaller red dwarf star, orbits around these two stars once every 10,000 years.
Article by Jorick Vink , Astronomer at the Armagh Observatory and Planetarium When you are fortunate enough to have a clear view of the night sky, and you start wondering about the properties of all these sources of light, you might be amazed to find out all these stars have Read more
Article by: Holly Preece, PhD student at the Armagh Observatory and Planetarium NASA’s Hubble space telescope was launched on 24th April 1990. It was the first optical space telescope to be launched into orbit and has been one of the most productive scientific instruments ever built. It orbits the Earth Read more
Article by Aaron Golden, Visiting Astronomer at the Armagh Observatory and Planetarium Stephen Bourke works at the Department of Space, Earth and Environment, Onsala Space Observatory in Sweden, and Aaron Golden at the School of Maths in NUI Galway, and is a visiting astronomer at the Armagh Observatory and Planetarium. Read more
Recent observations of the helium star HD144941 have been obtained from space. Armagh astronomers Professor Simon Jeffery and Dr Gavin Ramsay have discovered that they show a light curve best explained by darker and lighter patches on the star’s surface coming into view as the star rotates with a period Read more
Well, thankfully the drudgery of January is behind us and we can look forward to a month full of dark nights, stars and even a hint of romance. And let me tell you this my dear reader, if there’s one thing we’re experts on up in the Planetarium, it’s romance**. Read more
Some good news folks! If you fancy a few free ‘sparklers’ to get you celebrating, you could fill a bag with the number of fabulous looking stars that will appear their prettiest again this month against the darkest seasonal drape of the year as it stretches in all directions above Read more
Hello again Planetarichums! It’s Stephen here, ready to do my very best to explain some of the upcoming wonders in our night sky as we head into winter and the Christmas holidays. So, first things first, we’ll talk a little about our celestial neighbour, the Moon. On December 3rd our Read more
In a paper entitled ‘GALEX J184559.8−413827: a new extreme helium star identified using SALT’, Armagh astronomer Simon Jeffery reports the first new extreme helium star to be discovered in nearly 40 years. Extreme helium stars represent a small group of low-mass supergiant stars. They have spectral types equivalent to A Read more
October is over, and November is now upon us. The days are definitely getting colder, the night are definitely longer, which means the time for gazing into the night sky is now! One of the best things about November is the fact that there is not one, but two meteor Read more
On Aug 14th 2017 LIGO and the Virgo Gravitational Wave detectors based in the USA and Italy detected the fourth merging Black Hole event. This was a triumph for both groups, but especially the Virgo group which had only started taking regular data earlier that month. It did leave many Read more
Hello and welcome to my first attempt at an Astronotes blog! My name is Stephen and I’m finding out about our sky as I go during my time here in the Armagh Observatory and Planetarium. So, I hope you’ll join me on our journey through the October night sky. Read more
The Sun is a constant presence in everyday life from rising in the morning signifying the beginning of the day, to setting at night representing the time to rest. With the human race ever more dependent on technology it is important to monitor solar activity and the potential harm it Read more
Gaia is a satellite launched by the European Space Agency (ESA) on 19 December 2013. It is essentially a census gathering information on over one billion stars, totalling an amazing 1% of the galaxy’s total population, measuring their positions, motion, brightness and colour. Gaia’s primary objective is to create the Read more
A team of scientists in Australia are scanning the Universe for signals from extraterrestrial life. Professor Matthew Bailes, based at Swinburne University in Melbourne, is the lead scientist in this project funded by Russian billionaire Yuri Milner. Milner has donated $100 million and has the support of Professor Stephen Hawking. Read more
As the summer draws to a close September is a perfect time for stargazing before the cold nights of winter finally creep in. With sunset around 9pm and a forecasted heatwave, fingers crossed for some clear skies with some lovely mild temperatures. A key feature of the summer night sky Read more
During our school days, children in the developing and developed world could not even dream about getting a chance to look through a professional telescope; forget about playing with it for real observations! Those days, only the best professional astronomers/astrophysicists had access to such telescopic sites and networks. However one Read more
Michael Burton, Director, AOP On 27th July 2017, the RoI Minister John Halligan switched on I-LOFAR telescope, the largest radio telescope in the world, at Birr Castle in Co. Offaly. The Armagh Observatory and Planetarium is a member of the 8 institutions across the island of Ireland that came together to build I-LOFAR. Read more
Get your sunglasses on, and break out the sun tan lotion! July is here and we’re glad to see it. Summer is fully upon us and many of us will be on our summer holidays this month. The month of July was named after Julius Caesar by the Roman senate, Read more
It’s hard to believe that the summer has come around and we are half way through 2017. Time may be flying by but the good weather means a chance of clear skies at night and with lots to see this month let’s hope the rain stays at bay. Read more
The spring night sky has well and truly sprung, and although these months are sign of brighter evenings and therefore later bedtimes if you want star gaze, there are still lots of interesting patterns and objects that we can see. So let’s delve in and find them. The spring night Read more
Given that astronomy dates back to early written records from the Babylonians around 1600 BC if not earlier, black holes are a relatively new addition to human knowledge of the cosmos. Black holes cannot be seen therefore it took a long time for the first one to be found. Composed Read more
The Atacama Large Millimeter/submillimeter Array (ALMA) is a powerful instrument which can be used to observe the Sun at high spatial, temporal, and spectral resolution. ALMA consists of a giant array of 12-m antennas, with baselines up to 16 km, and an additional compact array of 7-m and 12-m antennas. Read more
Seventy thousand years ago our world, unmarked by agriculture and industry, was a very different planet. Back then Earth was shared by at least four separate types of human being. Tough and sturdy Neanderthal folk hunted mammoths and built huts across the chilly forests, mountains and plains of Eurasia. Further Read more
Astronomers world-wide are thrilled by news of a nova, just visible to the unaided eye in the constellation Delphinus (the Dolphin), just beside the familiar Summer Triangle. Why are they so excited and what will you see if you look toward this interloper in the sky? To stargazers in Read more
Our Solar System is old. Our best estimates from radiometric dating of meteorites suggest the Sun and its planets (including Earth) were forming some 4.6 billion years ago. The Universe itself appears to be some 13.8 billion years old based on its observed rate of expansion and the properties of Read more
Looking up in to the night sky it’s not difficult to see why the ancient Greeks believed that all the stars in the night sky were fixed on a celestial sphere revolving around the Earth and other planets. From our view on Earth the stars appear to be at a Read more
Zeta Reticuli, a dim binary system of Sun-like stars only 39.5 light years away in the little constellation of Reticulum is strangely well-known. Why is it so famous? This system was once identified as the home of the little grey-faced and black-eyed humanoids who allegedly abducted Barney and Betty Hill Read more
A globular cluster is made of hundreds of thousands or even millions of stars packed together in a pretty compact ball. The stars in globular clusters are old and there’s never any sign of new stars forming in them. Older stars are usually yellow, orange and red, so those colours Read more
Today Sirius, the brightest star in the night sky is an unmistakable blue-white in colour although it does twinkle a lot and can appear to change colour. However no one would think of describing it as red.It is thus a source of confusion that many ancient writers describe the star Read more
![Star types from left to right: a red dwarf, our Sun, a blue dwarf, and R136a1 (hypergiant). Where star sizes are measured by radius, from centre to surface, and where 1 solar radius is equal to that of our Sun (km) - R136a1’s radius is 35.4 times greater than the Sun [approximately 24.8 million km]. Credit: Author: ESO/M. Kornmesser](https://armaghplanet.com/wp-content/uploads/2012/03/image-of-star-types.jpg)
How big is the largest known star? Compared to planets, stars will always be the overall group winners in terms of superior size. When you look at the night sky on a clear night and away from city lights, you will see that there are stars of varying sizes and Read more
What was the Star of Bethlehem? Recorded only in the Gospel of Matthew, this mysterious celestial object is said to have heralded the Nativity. For millennia stargazers have wondered what it may have been. Now when Jesus was born in Bethlehem of Judea in the days of Herod Read more
A clear night sky is a thing of beauty and wonder. Thousands of scattered stars twinkle in the darkness. What are the stars? How do they live and die? Could an exploding star cause disaster on Earth? Over the past century or so astronomers have by observation and calculation established Read more
To observers on Earth, the great bull of Taurus has a fiery red eye. This is Aldebaran, an old red giant star which dwarfs our Sun. Let’s have a closer look at the facts and fiction about this aging star. If you go out after dark on a winter’s Read more
The giant star Betelgeuse will soon perish in a titanic explosion. Could this happen in the mythical “doomsday” year of 2012? Could dying Betelgeuse take us with it? “Beetlejuice! Beetlejuice! Beetlejuice!” was the chant which summoned the obnoxious ghost played by Michael Keaton in Tim Burton’s 1988 movie. Keaton’s character Read more
The smallest stars in the galaxy are the red dwarfs. Recent research suggests they are more common than previously suspected. Tiny, cool and dim compared to the Sun, they may seem unimportant. But consider this: red dwarfs not only outnumber every other type of star in the Universe but will Read more
Cepheid variables are massive, pulsating stars, valued by astronomers for the precise link between their brightness and steady pulsation. Let’s look at the history of Cepheid variables and how recent discoveries about these stars shatter established theories of stellar evolution. Cepheid variable stars have been known since the 18th Read more
What is light? Here’s an easy introduction to the electromagnetic spectrum all the way from radio waves to gamma rays. Before the modern era of technological astronomy, to know anything about the Universe beyond our planet we relied on light. We had to see planets, stars, and so on, to Read more
Imagine that once the Sun sets, rather than a dark sky sprinkled with a few thousand dim stars, we had a sky blazing with ten thousand or so stars blazing brighter than Venus. How different would astronomy, mythology, everyday life be? Planets orbiting stars in the NGC 3603 Young Cluster Read more
Here’s how rainbows are made. Some 13.7 billion years ago, a mere millionth of a second after the Big Bang, the first hydrogen and helium nuclei condensed out of a hot, dense soup of quarks and gluons. It took another 380 000 years or so for conditions in the ancient Read more
At first glance Gliese 710 is not a very distinguished star. A K7 class orange dwarf a bit more than half as massive as the Sun, it currently lies about 63 light years from us in the constellation Serpens. It is moving fast though and that is why one reason Read more
Around this time of year, go outside after 9pm on a clear night and look at the sky. Even if it is not quite dark a bright star will be visible in the south. This is Vega, the third brightest star in our sky (only Sirius and Arcturus are brighter). Read more