Snow moon, rogue planets and evolving galaxies

Waxing gibbous moon.

This high resolution image of a nearly full waxing gibbous Moon was taken by stitching 60 high magnification frames into a single montage. Each frame is composed of about 5,000 individual stacked photographs to compensate for moving atmospheric conditions we experience here on Earth. Therefore, this image comprises about 300,000 individual pictures! - Credit: Stephen Heliczer

If one of your New Year’s resolutions was to try your hand at amateur astronomy, there is no better practice than the Moon this February. The long nights make it an excellent target for observation.

This month there will be a full moon on the 16th, where you can get a full view of all the craters and mountains. Did you know a full moon in February is called a snow moon? In fact, all full moons have different names depending on the month.

Where did these names come from? Over in America, many Native American tribes have individual names for the different full moons throughout the year. The names were often based around animals, plants, or events that occurred during that month. When colonial Americans arrived, these names spread and became a part of popular culture worldwide.

February’s moon is called the snow moon due to the typically cold, snowy weather North America experiences during the month. However, depending on where you are at, the snow moon may also be known as the storm moon or hunger moon.

Astronomy at the University of Hertfordshire

How do we know how galaxies form if they take millions of years to change? By observing a lot of them! Since changes in galaxies take far longer than a human lifetime, astronomers create surveys of a large number of galaxies to make predictions on how galaxies form and change.

Using results from the Spitzer Survey of Stellar Structure in Galaxies, Dr. Aaron Watkins and his collaborators sought to investigate if there is a relationship between early-type galaxies (ETG) and late-type galaxies (LTG). ETGs are gas and dust poor with mostly old stars, while LTGs are gas rich and can have young stars.

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Their survey looked at 465 ETGs, measuring the surface brightness, sizes, and how their light changes with radius. An important result of their study shows how fitting their observations with multiple components is superior to using a single component fit.

They also found the central 1kpc core of most ETGs and LTGs are very similar, suggesting whatever leads to the differences between these types of galaxies has very little effect on the central part of the galaxy. These are all important results which help build a clearer picture of how galaxies evolve and inform future galaxy evolution models. 

This is just one of many interesting research results coming out of the astronomy department. If you want to keep up to date with the newest astronomy news coming out of the University, follow the department's Twitter account @I_Hert_Space.

Astronomy around the world

Rogue planets, what are they and why are they so elusive? These special planets are traveling alone through the stars, without a host star to orbit. Their origin is also a mystery. The idea of a planet wandering through our galaxy alone has been around in stories since the early 1900s, yet none were discovered until 2011.

Rogue planets are notoriously difficult to find since the lack of a parent stars means the planets do not shine brightly. Since their discovery, just 30 of these dark wanderers have been found. That is, until recently.

Astronomer Núria Miret-Roign from the Laboratoire d’Astrophysique de Bordeaux, France and the University of Vienna, Austria, lead a paper announcing the discovery of at least 70 new rogue planets.

How did they uncover so many when before only a handful were known? Knowing rogue planets do not shine brightly, they specifically looked for signals from young, large planets around the size of Jupiter. When these young planets have newly formed, they are still hot enough to be detectable.

Using 20 years' worth of archived observations, they carefully measured small changes from tens of millions of sources across the sky. Even with the wealth of new information, the origin of these planets remains a mystery. Do the planets form on their own, or are they flung out of another solar system and lost in space? While these new discoveries do not answer all our questions it is certainly an exciting start.