What’s in the sky this month?

Spring is here, and so is the Spring Triangle.

The Spring Triangle is an asterism made up of constellations.

What is an asterism?

An asterism is a pattern of stars recognised within a constellation.

The constellations Leo, Bootes, and Virgo are all visible in the night sky during the month of March.

By connecting the brightest stars from the three constellations, it creates the Spring Triangle.

To spot the Spring Triangle, look towards the south east horizon in the evening.

Want something a little more challenging?

Try looking for the International Space Station (ISS).

The ISS can be seen with the naked eye, however with some careful planning you could also catch it in a telescope and even take your own pictures.

The space station orbits the earth every 90 minutes, so when you can see it changes each day.

Websites like Spot the Station and Heavens Above can help you plan ahead to try and spot the space station.


Astronomy at the University Hertfordshire

If you want to simulate galaxies formation, you need to create an incredibly complex computer program.

You must decide what your starting conditions are, how small to make your simulated particles (hint, often the size of solar systems or galaxies!), what physics you are going to apply to your particles, how long you wait in between calculating the physics on each particle, and a multitude of other details.

All of these decisions can affect what your simulation produces and also affects how long it takes for the simulation to run.

To have an incredibly detailed simulation you might have to run it for months, or even years!

This means each decision to include any detail is carefully considered.

It is somewhat of an art, and figuring out what is important is high on the list of astronomer priorities.

One such issue in current simulations is the creation of dwarf galaxies.

We see many of these smaller galaxies throughout the universe and they are incredibly common.

However, in simulations we see far too many dwarf galaxies.

A recent paper by Faye Davis and her collaborators looked at 78 dwarf galaxies with active galactic nuclei (AGN) using data from three different optical and radio studies.

They sought to determine what information about these galaxies might be important for simulations to include. Specifically, they wanted to determine if AGN are important to dwarf galaxy formation.

An AGN is a supermassive black hole in the centre of a galaxy which is actively ejecting material.

AGN are known to be important in larger galaxies, as they affect how galaxies form and the environment around the galaxy.

The physics around AGN are not readily included in simulations, and Davis’s paper sought to justify including AGN in simulations by looking at their energy output, gas reservoirs, environmental conditions, and their host galaxy’s star formation rate.

Their findings supported AGN potentially playing an important role in dwarf galaxy formation, and they recommend simulations including AGN physics within dwarf galaxies.


Astronomy around the world

We know the best way to find a black hole is to look towards the centre of a galaxy.

Most galaxies, at their core, have a supermassive black hole.

However, we also know millions of massive stars may create a black hole once they reach the end of their life.

These black holes, while numerous, are much harder to find. They do not exist in some preferential location and they do not shine any light for us to spot.

After 10 years of Hubble Space Telescope observations, an international team of astronomers has found the first solo black hole.

They managed to track down the illusive object by carefully measuring the position of stars in the sky.

They looked for a tiny change in the brightness of a star, caused by a black hole passing between us and the star. This would bend the light, causing it to appear brighter.

After years of looking they were successful, finding a black hole 5,150 light years from Earth that crossed in front of a star.

This discovery is hoped to be one of many future discoveries. There are still many mysteries surrounding black holes and finding more lone black holes will help us better understand them.