When it's best to see Delta Aquariids meteor shower

The Delta Aquariids meteor shower.

The Delta Aquariids meteor shower and Milky Way over the Gifford Pinchot National Forest near Mt. Adams, Washington State. - Credit: Copyright © 2019 Diana Robinson

What’s in the sky this month?

This month the Delta Aquariids meteor shower will arrive, active from July 12 to August 23. While this year the moon will be bright in the sky during the peak of the meteor shower, if you can find your way to somewhere with dark skies you may still be able to catch some of the brighter ones!

The meteor shower will peak around July 29. The meteors are most likely to be visible starting at 2 am, peaking around 3:30am. You can expect around 25 meteors per hour.

To find the meteor shower, look south towards the constellation Aquarius. If you don’t know where to find Aquarius, look for Jupiter! The planet will be near the constellation all month.

The Hercules star constellation.

The Hercules star constellation. - Credit: Getty Images/iStockphoto

Several summer constellations are currently visible. At sunset, the constellation Hercules and to the south, just below Ursa Minor. If you have a clear view of the southern horizon, you may be able to catch a view of Sagittarius, the “teapot”.

Off to the east you’ll be able to spot Cygnus, often called the Summer Cross. To the north, you’ll see Cassiopeia, her throne shaped like a ‘w’ on the sky.

The Hercules constellation.

The Hercules constellation. - Credit: Getty Images/iStockphoto

Astronomy at the University of Hertfordshire

Can clouds be made out of quartz? In space they can! Dr Ben Burningham and collaborators recently published a paper studying the composition of clouds in the skies of a nearby brown dwarf, which can be thought of as both a failed star and a super planet.

Studying the atmospheres of brown dwarfs helps us understand how exoplanets form and evolve. Using observations collected from previous studies, they created computer models to try and recreate the compositions of the clouds.

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Depending on the make-up of the cloud, the light is blocked at different wavelengths. This allows models to try out clouds made of different materials to find which one fits what we see. From their models, Dr Burningham and his collaborators identified three specific substances primarily responsible for blocking the light: iron, quartz, and enstatite. They found the clouds are made up of materials in different quantities than what we see in our solar system.

This is exciting, as many exoplanet formation models assume clouds will be composed similarly to our solar system. Dr Burningham’s results show this is not necessarily the case, and more varied models are needed.

Do adolescent stars act up frequently? Yes, and when they act up they get brighter!

Dr Zhen Guo and his collaborators have published a study looking at several of these flaring pre-stars. Young stellar objects, called YSO’s, are not-quite-stars. They are collecting materials from their surroundings, and have yet to get large enough to start fusing hydrogen like mature stars do.

The material collects in a disk, spinning around the star. Over time, the accretion stream could suddenly enhance, which allows a significant amount of surrounding material to fall onto its surface.

As this happens, the YSO’s brightness and activity can vary, getting somewhat 10 to 100 times brighter when material falls in and then dimming again. This cyclical brightening and dimming can take place over a span of months to several decades.

Dr Guo and his collaborators have identified 33 YSO’s towards the galactic centre which all appear highly variable. By investigated this variability, they can learn what is controlling the star's growth. They found several of the YSOs’ disks, and thus variability, is controlled by the magnetic field of the YSO.

Studies like Dr Guo’s are important for learning how stars form, what controls their evolution, and even how planet forms under these chaotic circumstances.

Latest astronomy news from around the world

China has landed their Zhurong Mars rover and is streaming back pictures! The 240kg rover is exploring Utopia Planitia, the largest impact basin on Mars.

Its mission includes studying the local topography, zapping rocks and soil with a high-powered laser to measure their chemical composition, and studying the atmosphere. The rover is planned to have a 90 day mission, but like all Mars rovers, is hoped to last far longer than its planned mission time.