Mir and I went on an unexpected aurora chase following the NASTRO meeting last night. Conditions weren't great: an almost full moon washed out the northern sky. If not for that this would have been one the best displays of the year.
Here's a panorama taken from the dunes at Low Hauxley. The lights of Amble on the left and the lighthouse on Coquet Island on the right.
The shimmering activity died away shortly after this picture was taken leaving a steady green arc of light. The picture below was taken near Warkworth from the bank of the river Coquet.
.We're heading towards an equinox so hopefully conditions for aurora chasing will improve and the moon will soon depart the evening sky.
Venus is at inferior conjunction today. That means it positioned between the Earth and Sun.
When the alignment is exact Venus is seen to transit in front of the Sun. At most inferior conjunctions the alignment is not exact and Venus passes above or below the Sun. That was how things were today; Venus passed just under 8 degrees south of the Sun.
Here is the simulated view provided by Stellarium:
It's very difficult to observe Venus under these circumstances. The planet isn't visible to the naked eye. It's so close to the Sun that even when the telescope is aimed at Venus some sunlight can still enter the optical system and cook the inside of the telescope!
I was using a Celestron NexStar 102SLT to observe Venus. The telescope is tracking Venus on the HEQ5 Pro mount. Without being able to do a polar alignment in daylight it was fairly tricky to find Venus. My method was to get the 'scope pointed at the Sun (and then correctly focussed) with a solar filter in place. Then I offset the telescope by the required number of degrees in RA and Dec and hoped for the best after removing the solar filter.
Venus was relatively easy to see once it entered the field of view. A razor sharp white crescent against bright blue sky. The air was a little turbulent and that stopped me getting a good picture with the camera. I did get the crescent though:
Venus has been visible in the evening sky after sunset since late 2014. After today it is technically a morning sky object - visible before dawn. Venus will be shining in the morning sky before sunrise before the end of the month.
I'm giving a presentation at NASTRO in few minutes. The PDF of my talk can be found on my astronomy lectures page. Click here!
During the summer in doesn't get dark in Northumberland; just a lingering twilight after the Sun goes down. This week astronomical darkness has returned and I've started observing and imaging again.
Last night I too this picture of a little twinkly orange star in the constellation Scutum (the Shield).
The star at the centre of the picture is called UY Scuti. It is very dim - a telescope is needed to pick it out of the thousands of Milky Way stars in the same field of view.
However this is no normal star. UY Scuti is a candidate for being the largest star in the entire Galaxy. Astronomers believe the actual size of UY Scuti is as shown in the picture on the right: big enough to hold 5 billion Suns!
The distance from here to UY Scuti is thought to be around 9,500 light-years and we're viewing it through the gas and dust of the Milky Way's spiral arms and that's why it seems to shine so feebly in the night sky. Appearances are often deceptive in astronomy and UY Scuti is actually about 340,000 times more luminous than the Sun. If UY Scuti were to replace the Sun at the centre of the solar system then the Earth would be inside the star. Along with Mars and Jupiter.
Despite all of this UY Scuti is not that massive - only 7-10 times the mass of the Sun. The density of the star is very low and surface gravity at the boundaries of the star are low too. Red supergiants lose material to the wider universe in solar winds a million times more powerful than the Sun produces. At the end of their lives, they all end with a bang as a type II supernova. At our present distance this would make UY Scuti visible to the naked as it temporarily becomes brighter than even Venus can be in our sky.
I've waited a long time to see pictures of distant Pluto. When I was young pictures of Pluto were just as a point of light (usually one or both of the discovery plates) taken by Clyde Tombaugh in 1930.
Some of my astronomy books had the discovery image of Pluto with its biggest moon, Charon, which was seen as a slight bump on Pluto. The two were only partially resolved through the best Earth based telescopes in the world back in 1978.
The superior optics of the Hubble Space Telescope were able to clearly resolve the two worlds clearly in 1994.
And now the New Horizons spacecraft is just days away from a brief flyby of the Pluto system. Compare the view above to this one snapped by the spacecraft yesterday.
Today was graduation day for those students that started my course last September. Most were happy but not all of them passed. It's been a hectic few weeks dealing with the admin side of their course ending too: exams, resits, marking and preparing stuff for the external examiners. All the while teaching the other cohort of students.
In the next couple of weeks I've got a deadline approaching to finish changes to my course textbook (two of them!) After that....the days of calm. From next week I'll be down to just 49 students (those that started in January) and 7 hours of teaching per week until they leave in the summer.
Finally found a bit of time to get a star chart for the June night sky done.
Based on my location in Northumberland - download the high quality PDF here because it contains a lot more information about the star chart and some of the stars, planets and other sights visible in the sky this month.
I'm a big fan of LaTeX and PSTricks and I use them often to create diagrams and graphs for my various maths and astronomy lecture notes. But to create this lunar phase diagram it was much more convenient to use another package called TikZ!
It's a pretty standard diagram; sunlight is shown streaming from the right. The Earth is at the centre with the moon shown in a (blue) circular orbit and presented at various positions around the orbit. The phase of the moon (the shape of the illuminated portion we see from Earth) is shown outside the orbit. I added some arrows and arcs to show the traditional waxing (growing larger) and waning (growing smaller) sections of the orbit and finally, the number of days since new moon.
Technical details of the code below the fold.
I don't think the MESSENGER mission to Mercury ever captured the imagination of the general public in the same way Cassini is still doing at Saturn. MESSENGER ended its 11 year mission yesterday. With no more fuel aboard the spacecraft the peturbing force of solar gravity finally brought MESSENGER down with a bang on the surface. Prior to 2011 Mercury was a largely unknown planet with just one-third of its surface imaged in the 1970s. MESSENGER has transformed our view of Mercury since its first flyby in 2011 and sent back views of the planet like these:
Mercury has clearly been battered and scarred from impacts sustained since the earliest days of the solar system.
Meanwhile, on the other side of the solar system the New Horizons spacecraft is hurtling towards a July rendezvous with an ex-planet called Pluto. New Horizons is now close enough to Pluto - a world even smaller than Mercury - for its cameras to pick out surface details:
NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
The orbiting moon is called Charon and it's quite big compared to Pluto. Pluto appears to wobble because the centre of mass (the barycentre) of Pluto and Charon is some way outside Pluto. The close-up view shows a lot of variation in brightness across the disk. Clearly Pluto is going to be an interesting place to see when New Horizons eventually arrives!
Had long walk today up on Simonside Hills near Rothbury. Fantastic view across a lot of Northumberland. Made a panorama to try and convey what the view is like from the top:
Hope to go back in the future to visit the solstice stone.
Dr Adrian Jannetta
Guitar strummin' explorer of the universe. Mild mannered maths teacher by day and astronomer by night.