Have you ever wanted to name a planet? Well now here is your chance! The International Astronomical Union (IAU) is running a competition to name an exoplanet - a planet around another star.
Some of the planets the IAU are seeking new names for are currently called HAT-P-12b or WASP-121b. That is because there are rules on naming things in space, and the IAU, which is the official international body of astronomy, has the authority to name objects in space.
When it comes to an exoplanet, it is given a catalog name, usually after the survey that either first found the star, or the planet. HAT is the Hungarian Automate Telescope network, with small planet-finding telescopes around the world, including at our dark sky site, Siding Spring Observatory. WASP is named after the Wide Angle Search for Planets.
Usually, the planets just keep the catalog name. The IAU though has chosen some of the most interesting exoplanets to bear new names for this competition.
There are more than 5000 exoplanets already discovered, and coming up with names for all of them is a big task, which is why the simple catalog name usually stays.
Stars and galaxies are even worse. With about 300 billion stars in our Milky Way, there is no way to name them all, let alone a small percentage. We also think there are as many as 2 trillion galaxies in the Universe as well.
Instead up of coming with names for all of these, most of them have boring, long telephone-sounding names, such as SMSS J031300.36-670839.3.
However, this serves a purpose as this is actually the star's co-ordinates in space - their space latitude and longitude. It means that an astronomer can easily figure out where it is in the sky and locate it, without having to look up the name in a database, and then find its position.
With SMSS J031300.36-670839.3, the SMSS is in the SkyMapper Southern Survey followed by the right ascension (or space latitude) and declination (or space longitude).
Some bright stars, ones that have been visible to humans through history, have proper names, but most have alphanumeric names or designations. These numbers, while sounding boring, belong to one of two naming/designation schemes. For instance, some follow an alphabetic order based on brightness and the constellation they are in.
Betelgeuse, the Dog Star, is the bright star in the constellation Orion. Betelgeuse is also designated Alpha Orionis. Alpha is always the brightest star in the constellation followed by the constellation name. So there is a Beta Orionis, Delta Orionis and so on, and also an Alpha Crux, Beta Crux, etc. in the Southern Cross.
Every type of object has a different set of rules for naming. For example, asteroids can be named by the discoverer. However, the name has to be a certain length, a real name in some language (no, you can't make up a language), and non-offensive. It also can't be named after yourself.
This is very different for comets, which must be named after the discoverer. For instance, there are actually many Comet McNaughts - as Robert McNaught has discovered dozens of them.
Of course, there are also alpha-numeric IDs for both asteroids and comets to limit confusion.
So if you do not plan on discovering your own exoplanet or other object, here is your chance to name an existing one.
More information is at: https://www.nameexoworlds.iau.org/2022methodology
- Brad Tucker is an Astrophysics and Cosmologist at Mt Stromlo Observatory and the National Centre for the Public Awareness of Science at the ANU.
