FAQs

Below you will find a list of FAQs asked from us in public events and outreach activities. Please do not hesitate to send us any questions that you have regarding this project or about astronomy in general and we will include it here.

Topic: Jobs in Astronomy

Q. What does an astrophysicist do?
Q. Why do you collaborate internationally?

Topic: The StarFormMapper Project

Q. So what is the StarFormMapper project?
Q. ..and Gaia is?
Q. What about Herschel?with which
Q. What is a space observatory?
Q. How is your research funded?

Topic: Stars, our Galaxy, and Beyond!

Q. What are stars made of?
Q. How many stars are there in our Galaxy?
Q. Are all stars the same?
Q. I hear that astronomers sometimes talk about the “magnitude of stars”. What is that?
Q. How are the absolute magnitudes of stars measured?
Q. Why do you measure distances in parsecs and not meters?

Q. Do solar flares enable the formation of life on planets?


Q. What does an astrophysicist do?

A. We study objects in space (planets, stars, galaxies) and try to figure out how they work.


Q. Why do you collaborate internationally?

A. In short – there are not that many of us! There are many different topics in astronomy (stars, planets, galaxies etc.) and even more sub-topics within those topics! For example, if you were interested in stars you could study (to name a few): Giant Molecular Clouds, cold cores and filaments, protostars, main sequence stars, post-main sequence stars, stellar remnants, open star clusters, globular clusters. Normally an astrophysicist will choose to focus on one or two of these sub-topics in their career. To advance knowledge and understanding in any scientific field you need to collaborate with (the typically small number of) other people working on a similar problem/topic as yourself, who could be located anywhere on the planet.

Another reason to collaborate internationally is to share resources, such as telescopes.


Q. So what is the StarFormMapper project?

A. StarFormMapper (SFM) aims to combine data from two of ESA’s major space missions, Gaia and Herschel, together with ground based facilities, to constrain the mechanisms of massive star and star cluster formation.


Q. ..and Gaia is?

A. Gaia is a space observatory operated by the European Space Agency (ESA). Gaia was launched in December 2013. During the course of its 5 year mission, it will observe around 1 billion objects (mainly stars) which translates into 0.5 percent of all stars in the Galaxy. While this might seem like a very small fraction, astronomers are able to do some exciting science even with this tiny fraction and put constraints on the formation and evolution theories of stars and the Milky Way galaxy.


Q. What about Herschel?

A. Herschel was a space observatory operated by the European Space Agency (ESA). It operated between 2009 and 2013. During the course of its 4 year mission, it observed objects in our solar system, stars in our Galaxy and other Galaxies. Unlike Gaia, Herschel observed a special kind of light from these objects known as Infrared.


Q. What is a space observatory?

A. Space observatories are like ground based observatories, but are in space! The quality of the images taken by ground based observatories are hampered by the Earth atmosphere. As a result, by sending observatories to space the effect of atmosphere is eliminated which leads to a significant improvement to the quality of the images.


Q. How is your research funded?

A. We are funded by the EU through their Horizon2020 program – its largest Research and Innovation programme ever. Horizon2020 aims to build research networks and strengthen international collaboration across the European Research Area, promoting public and private sectors to work together to ultimately produce breakthroughs, discoveries and world-firsts.


Q. What are stars made of?

A. Primarily Hydrogen, which is converted to Helium and then heavier elements over the course of a stars lifetime via nuclear fusion.


Q. How many stars are there in our Galaxy?

A. It has been estimated that there are about 400 billion stars in our Galaxy.


Q. Are all stars the same?

A. Nope! Stars can be anywhere between 150 and 0.1 times the mass of our own Sun.


Q. How are stars made?

A. There are very large clouds made up of gas and dust in our Galaxy (called ‘Giant Molecular Clouds’) which accrete more gas and dust over time. Eventually gravity causes these clouds collapse and form many stars which are typically clustered together (we call these ‘star clusters’).


Q. I hear that astronomers sometimes talk about the “magnitude of stars”. What is that?

A. The magnitude of a star is a measure of how bright it is. In astronomy, we define two types of magnitudes for stars: apparent magnitude (how bright it appears when we observe it) and absolute magnitude (how bright it really is). The apparent magnitude of a star depends on [1] its mass (the more massive the star, the brighter it really is) and [2] its distance from Earth. The magnitude of a star can be any number and conversely, the smaller its value the brighter the star! For example, a star with a magnitude of -5 is much brighter than a star with a magnitude of 10.


Q. How are the absolute magnitudes of stars measured?

A. It is the how bright the star would be if it was located at a distance of 10 parsecs from the Earth. A parsec (pc) is a unit of measuring distance in astronomy and approximately equal to 3.1×1017 meters or 3.26 light-years.


Q. Why do you measure distances in parsecs and not meters?

A. The distance to astronomical objects is so large that meters or even kilometres are too small a unit – its like trying to measuring your height in millimetres. For example, Proxima Centauri is the nearest star to the Sun at 1.3 parsecs away (40,000,000,000,000,000 meters)!


Q. I recently read that planets may need a certain level of UV radiation, in addition to being in the Habitable Zone, for life to start. If life is found on one of Jupiter’s moons or on Pluto would that mean that our Sun must have had flares of sufficient strength and duration for life to form, or does that mean that life could not have started on those locations?

For a planet to create life the conditions have to be just right. Research into the exact conditions required is ongoing, with recent studies suggesting sufficient UV light is needed to cause the chemical reactions to form RNA. What we do know is that for life to form liquid water is a fundamental requirement. The Habitable Zone is a region within a certain distance of a star in which an orbiting planet can have liquid surface water (i.e. the surface temperature is not too hot or too cold). In our solar system Earth and Mars fall within the Habitable Zone, so naturally searches for life have focused on Mars. However, this does not discount the possibility of life outside the Habitable Zone as liquid water could potentially exist below a frozen surface of dwarf planets or one of the moons of the gas giants.

Stars are blackbodies – that is to say they continuously give off radiation across the entire electromagnetic spectrum, including UV radiation. The team of scientists behind the research into UV radiation as a requirement for life determined that a planet would need to be in an “Abiogenesis Zone” which is a region within a certain distance of a star with which a planet gets consistently enough (but not too much) UV radiation from the star. Solar flares are sporadic eruptions from the surface of the Sun that last a few minutes to a few hours and vary in intensity, so would not be a sufficient source of radiation for life to form.


 

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