SGR J1745−2900, or PSR J1745−2900, is the first-discovered magnetar orbiting the black hole Sagittarius A*, in the center of the Milky Way.

[1][2] The magnetar was discovered in 2013 using the Effelsberg 100-m Radio Telescope, the Nancay Decimetric Radio Telescope, and the Jodrell Bank Lovell Telescope.

The magnetar has a period of 3.76 s and a magnetic flux density of ~ 1010 T (1014 G).

The magnetar, which is also a pulsar, is 0.33 ly from the central black hole.

The object offers an unparalleled tool for probing the ionized interstellar medium (ISM) toward the Galactic Center (GC),[3] and a possible way to test quantum gravity effects.