James Webb Space Telescope turns on its antenna; NASA reveals first interstellar target

The James Webb Space Telescope (JWST) arrived at its destination at the second Lagrange point on January 25, a milestone that has set the stage for historic cosmic discoveries. Currently in its commissioning phase, Webb is 15 lakh kilometres from Earth and the engineers behind this multi-billion dollar equipment are aligning its mirrors to prepare it for the mission ahead. In the process, NASA said that Webb's 'high-gain' antenna has been turned on and revealed the telescope's first target out there. 

A Sun-like star revealed as Webb's first target

In a new blog post, NASA revealed that Webb will begin its exploration journey by pointing at a Sun-like star named HD 84406. This star is about 260 light-years away from Earth and will be used to gather engineering data so that engineers can align Webb's mirrors for further observations. According to the agency, Webb's target is located in the Ursa Major constellation and has been selected as Webb can spot it at this time of the year. 

"HD 84406 will be too bright to study with Webb once the telescope starts to come into focus. But for now, it is the perfect target to begin our search for photons, a search that will lead us to the distant universe", NASA said in its blog. 

As for the antenna, the agency stated that it is a high-gain antenna that offers a higher data rate than the radio band used by the telescope until now. It is this antenna that will later allow the transmission of images and data back to the Earth. 

Webb's journey from Earth to the Lagrange point

The telescope lifted off from the Kourou spaceport in French Guiana on an Ariane 5 rocket and has covered a 15 lakh kilometer journey to reach the second Lagrange point (L2). Since Webb's instruments need to be at an extremely cold temperature to detect infrared light, this location would save it from the Sun's heat. At L2, Webb will soon activate its four instruments-  the Near Infrared Camera (NIRcam), the Mid Infrared Instrument (MIRI), the Fine Guidance Sensor and two different Near-Infrared Spectrographs to peer 13.5 billion years back in time.

Image: Twitter/@NASA