A new active region has moved onto the Sun’s disk.
However, it may not be a completely new sunspot as this seems to be the old active region AR 3736, which was very active with flares a couple of weeks ago, before it rotated behind the Sun’s disk.
See my Blog entry for the images and animation I took of it on the 24th of March:
This active region seems to have lasted and continued to develop while it was behind the Sun, until it has now re-emerged from behind the Sun’s disk and been assigned a new AR number 2738.
Here are my images of the active region in white light (left) and Hydrogen Alpha.
