Whirlpool Galaxy (M51) Whirlpool Galaxy (M51), one of the galaxies studied by Chakrabarti
and co.,has a satellite galaxy residing in its short spiral arm – marked in the image with an "X."
The distribution of hydrogen in M51 extends far beyond the visual boundaries of the galaxy, and
perturbations in that hydrogen make it possible to infer the location and mass of these "dark" satellites.

Sukanya Chakrabarti/UC Berkeley

 

Some astronomers spend their careers peering at and discovering distant galaxies; Sukanya Chakrabarti is trying to discover one a lot closer to home. Chakrabarti, a post doctoral fellow and theoretical astronomer at UC Berkeley has developed a mathematical formula that she says can identify and measure small, “dark” satellite galaxies orbiting larger galactic disks, and she thinks she’s found an undetected one just on the other side of the Milky Way from Earth, obscured from our view by the dust and gas in the galaxy.

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