GRAVITY Instrument拍銀河中心
http://astronomynow.com/2016/06/23/successful-first-observations-of-galactic-centre-with-gravity-instrument/Image of the galactic centre. For the interferometric GRAVITY observations the star IRS 16C was used as a reference star, the actual target was the star S2. The position of the centre, which harbours the (invisible) black hole known as Sgr A*, with 4 million solar masses, is marked by the orange cross. Image credit: ESO/MPE/S. Gillessen et al.