Twitter Facebook Flickr YouTube

June 2015: Real

June 2015

In the show this time, we talk to Dr. Debora Sijacki about cosmological simulations, Indy rounds up the latest news, and we find out what we can see in the June night sky from Ian Morison and Claire Bretherton.

The News

In the news this month: the origin of jets, another Kuiper Belt and the future of telescopes on Mauna Kea

Interview with Dr. Debora Sijacki

Dr. Debora Sijacki from the University of Cambridge is a cosmologist who specialises in developing large-scale simulations of our universe. She describes the basic principles behind building simulations of very large chunks of the universe, and explains what we can learn about various astrophysical phenomena from these simulations. Dr. Sijacki also talks about the limitations of numerical models, and what the future holds for an ever more useful tool used to explore cosmology.

The Night Sky

Northern Hemisphere

Ian Morison tells us what we can see in the northern hemisphere night sky during June 2015.

The constellation of Leo the Lion is setting in the west after sunset, with the asterism of the Sickle forming its mane and Regulus as its brightest star. The planets Jupiter and Venus are both found here later in the month. Towards the South is the Realm of the Galaxies, in Virgo and Coma Berenices, where a telescope can pick out many deep-sky objects. The bright star Arcturus, in Boötes, resides nearby. Cygnus the Swan and Lyra the Lyre are rising in the east, with Hercules in between them and Boötes. The Summer Triangle, composed of the stars Altair in Aquila, Deneb in Cygnus and Vega in Lyra, is visible. One third of the way from Altair to Vega lies the Cygnus Rift, a dark region of dust in the Milky Way, which hosts Brocchi's Cluster, also known as the Coathanger. Ursa Major is almost overhead.

The Planets


Southern Hemisphere

Claire Bretherton from the Carter Observatory in New Zealand speaks about the southern hemisphere night sky during June 2015.

The winter solstice occurs on the 22nd (New Zealand Standard Time or NZST, 12 hours ahead of Universal Time) of this month, when the southern hemisphere is at its greatest tilt away from the Sun and the hours of daylight are at their shortest. The word 'solstice' indicates that the Sun is still, because it rises and sets at its most northerly points before moving south again. Brilliant Venus and golden Jupiter appear in the north-west after sunset, getting closer together as Venus ascends and Jupiter descends in the sky. They are joined by the crescent Moon on the 20th, and by the end of the month the two planets are less than one Moon diameter apart.

The centre of the Milky Way, in the constellation of Scorpius, rises high in the sky when seen from the southern hemisphere, and is currently midway up the eastern sky in the evening. The winter constellations of Scorpius and Sagittarius will dominate the night sky over the next few months. The red giant star Antares marks the heart of Scorpius, the Scorpion, and a near-vertical line of stars to its left represents the Claws. Saturn, at magnitude +0.8, is a little further left still, with an almost-full Moon passing within 1.5° of it on the 2nd. Scorpius is known to Māori as Te Matau a Māui, the Fish-hook of Māui. The mythical figure Māui used this to pull a giant fish from the ocean, which became Te Ika-a-Māui, the North Island of New Zealand. Antares is called Rehua, representing a drop of blood from Māui's nose that he used as bait. Scorpius was an important navigation aid in the South Pacific, as it moves overhead and shows the directions of east and west that would bring sailors to Aoteroa (New Zealand). Below the Fish-hook, the brightest stars of Sagittarius make the shape of an upside-down Teapot, and many star clusters and nebulae line the Milky Way in this part of the sky. M7, an open star cluster visible to the naked eye, sits about halfway between the stinger of the Scorpion and the spout of the Teapot. The nearby Butterfly Cluster, M6, is a lovely sight in binoculars.

The Māori new year, Matariki, happens this month when the Pleiades star cluster, also called Matariki, rises at dawn. Scorpius is on the west-south-western horizon at this time of year, with the Fish-hook pointing upwards, and Orion the Hunter is on the opposite side of the sky, rising due east. The three stars of Orion's Belt, known as Tautoru, line the horizon, and point to Sirius on their right. Sirius is called Takarua, and is the brightest night-time star. Following the Belt left leads to the V-shaped head of Taurus the Bull, with the orange star Aldebaran marking his Eye, and then to Matariki as it rises in the east-north-east. The Pleiades disappear from the sky in April, and their reappearance in early June indicates that the new year is approaching, with the next New Moon (or, in some areas, the next Full Moon) marking the actual turn of the year. This month, the New Moon happens on the 17th. Matariki, Tautoru, Takarua and Rehua are the four points of a celestial compass used to navigate the Pacific Ocean, with Matariki and Takarua marking the extremities of the Sun's rising points, Tautoru placed at one end of the celestial equator (the star Altair being at the other) and the Sun and planets moving along the line between Matariki and Rehua. They are also the four pillars, or Pou, holding up the Sky Father, Ranginui or Rangi, in Māori lore.

Odds and Ends

An unusual Wolf-Rayet star, with the unfortunate nickname of Nasty 1, could be an insight into the formation of these unusual stars. Wolf-Rayet stars are massive stars that have lost their hydrogen envelope, exposing their fusion core. Nasty 1 has been caught by the Hubble Space Telescope during a brief stage in which a companion star is stripping it of its hydrogen. The process is rather inefficient, and forms a huge pancake-like disk of gas 2 trillion miles wide (that’s a sixth of the way between the Sun and Proxima Centauri). It is thought that this may be a glimpse into the way Wolf-Rayet stars form.

Scientists using the Mars Reconnaissance Orbiter have found what appear to be long thin flows of salty water on the surface, one of which is fairly close to the Curiosity rover. The find raises questions over planetary protection, and how much we should interfere with possible life-bearing environments on other planets.

The Planetary Society is a nonprofit organisation dedicated to the development of future space technologies, exploration, education and of citizen space programs. It is currently involved with a project to demonstrate the proof-of-concept of solar sails, called the lightsail mission. The first phase of the mission, to test the deployment mechanism of the sail, was due to begin last week, however a software glitch has rendered the tiny satellite (known as a cubesat) incontactable, and now the team await a passing particle to reboot the system (which is not as rare as you'd expect)! The cubesat is currently chilling in a low-earth orbit, and you can find the full story here, or to follow the mission's updates live, check out this page. And if you want to get involved, why not take a look at the mission's Kickstarter page?
Update:It's alive!

Show Credits

News:Indy Leclercq
Interview:Dr. Debora Sijacki and Indy Leclercq
Night sky:Ian Morison and Claire Bretherton
Presenters:Charlie Walker, Indy Leclercq and Hannah Stacey
Editors:Charlie Walker, Indy Leclercq and Mark Purver
Segment Voice:Iain McDonald
Website:Indy Leclercq and Stuart Lowe
Website:Indy Leclercq and Stuart Lowe
Cover art:An artist's impression of a disk of gas surrounding a Wolf-Rayet star which is being 'cannibalised' by a smaller companion star. This is the scenario envisaged for the NaSt1, or 'Nasty', star. CREDIT: NASA/ESA/G. Bacon (STSci)

Download Options

Subscribe (It's free)