What’s in the sky this month?

Things have quietened down in the sky this month after the end of the Perseid meteor shower. However, that doesn’t mean there isn’t anything to see! Mercury will soon be at its greatest distance from the sun.

As Mercury is the closest planet to the sun, it is only visible close to sunrise or sunset. On September 10, there is a chance to view Mercury just after sunset, along with Venus and a thin crescent moon.

To see Mercury, you’ll need to look towards where the sun set, just above the horizon. You might want to use a telescope or binoculars, as the twilight light can make the planet hard to see.

Mercury isn’t the only hard to spot object you can see this month. Andromeda, also known as M31, is one of the nearest galaxies to our own and is visible to the northeast. To see it with the naked eye, you will have to go to a very dark site. Still, you might be able to faintly pick it out after 9pm.

Look for the constellation Cassiopeia, then look beneath it to the right to see if you can spot the constellation Andromeda. The galaxy Andromeda lies just above it. Once again, a pair of binoculars or a small telescope will make viewing far easier!

Astronomy at the University Hertfordshire

From gold plated telescopes in space to neutrinos detectors deep in the earth, astronomers have been finding innovative ways to use technology to expand their observing capabilities.

At the University of Hertfordshire, PhD student Piyamas Choochalerm has been investigating ways to use commercial optical fibers to better improve spectroscopic observations.

Fibre optic cables are commonly used in astronomy to capture light and focus it. The light can then be spread out into a spectrum, allowing astronomers to study the wavelengths of light that comprise the incoming observations.

The research led by Piyamas is seeking to develop a fibre optic system that can be used on small telescopes, with dishes 1-3 meters in size.

By tapering the fibre optic cables, the setup can also simplify the often-complex system used by larger telescopes.

This enables a more “off the shelf” approach for setting up the systems rather than the custom, complex equipment often required.

The team’s research took various commercial fibres and tried tapering the cables to test how well they performed. Tapering can make a smaller beam sizes on the sky which in turn allows for objects in the sky to be studied in finer detail. In their study, they found tapering an effective method for creating a smaller spectrograph, specifically when using a graded index taper.

Using commercially available fibres with tapering will help make these spectroscopic systems cheaper and more widely available.

Astronomy around the world

The saying goes, two’s company, and three’s a crowd, but for supermassive black holes three might be just right! A group of researchers from the Indian Institute of Astrophysics have detected a galaxy merger involving three different galaxies.

Almost every galaxy has a supermassive black hole at its centre. When two galaxies approach each other and begin merging together, the supermassive black holes may become caught in each other’s gravity, slowly spiralling together.

To come closer together, the black holes must reduce their kinetic energy. They can do this by flinging away nearby stars and gas that falls into their orbit via gravitational interactions.

However, once the black holes have gotten to within a parsec of each other, there is often not enough stellar or gas matter to fling away so that the black holes can merge.

This is where a third supermassive black hole comes in. If a third galaxy interacts with the merging galaxies, the smallest of the three black holes can be flung away, removing enough energy from the system to merge. Finding a system of three supermassive black holes is an important step in understanding how our universe evolves.