Urgent Request for Observations - Cygnus X-3

A great opportunity has come up for FT users to help collect data to contribute to research being conducted by several astronomy groups around the world.

A binary system believed to contain a massive star known as a Wolf-Rayet star and a neutron star has increased hugely in brightness over the last couple of weeks. A Wolf-Rayet star is an evolved star of >25 solar masses, which is losing mass as a result of a prodigious stellar wind.

The fact that these stars are in a compact binary means that a huge amount of heat is generated as material is drawn onto the neutron star (accreted). This 'heat' is given off as X-rays, meaning that these type of systems are known as X-ray Binaries (XRBs). Cygnus X-3 belongs to an enigmatic class of XRBs, known as microquasars, where the system itself produces 'jets' of energy and/or matter that come out of the system at right angles to the plane of the orbit as in the artist's impression below.

In the radio, the increase in brightness is a factor of around 1500 ! This outburst suggests that something extremely powerful and interesting is underway. 

Since this system has brightened so spectacularly, it has come to the attention of

many astronomers who work in different parts of the electromagnetic spectrum. This means that the data we're hoping schools can help us collect will be added into a pool of data from ground-based observatories such as the VLA (radio) and space-based telescopes such as Integral and Swift (X-ray).

A set of radio images of the system from an outburst a few years ago is shown below and shows the jets 'expanding' into the environment around the binary.

FT North has recently installed new filters, some of which take us towards the infra-red. These allow us to image this system in a way that isnt possible with normal 'optical' filters. In the optical, this system is shrouded both in its own dust, and also due to its location towards the Galactic Centre.  

The system is only visible from FT North, on any RTI session after 12 UT (1PM BST).

What we would like any user of FT North for the rest of April to do is to take one image each in Z and Y bands of 25 seconds centred on the following co-ordinates 

RA 20:32:25.8

dec +40:57:27.8 

The image type required is stellar.   

For any further information, please email me lewisf 'at' cf.ac.uk