Supernova

Normal sudoku rules apply.

Divide the grid into galaxies: orthogonally connected groups of cells that have 180 degree rotational symmetry about their centers (marked with a small dot). All cells must be part of a galaxy; no galaxies overlap.

Grey dots mark "renban" galaxies: those with two or more cells, whose digits form an unbroken consecutive sequence in any order. White dots mark galaxies whose digits do NOT form a sequence. Digits may not repeat within a galaxy.

As per Galactic Map Standards: All galaxies with at least TWO cells indicate their SMALLEST digit with a diamond icon. All galaxies with at least SIX cells indicate their LARGEST digit with a circle icon.

There is ONE single-cell galaxy -- the "Supernova" -- that is not marked: its location must be deduced by the solver.

Draw eight straight lines radiating out from the supernova to the edge of the grid. Starting from the supernova and travelling outwards, digits along each line strictly decrease. (You can think of the lines as thermometers with their bulbs at the edge of the grid and their tips all in the supernova cell.)