Reconstructed spectrum of light spread out from the ultra-diffuse galaxy, DragonFly44, as seen by the Keck/LRIS instrument. Credit: P. Van Dokkum, R. Abraham, J. Brodie
Reconstructed spectrum of light spread out from the ultra-diffuse galaxy, DragonFly44, as seen by the Keck/LRIS instrument. Dark bands occur where atoms and molecules absorb the galaxy’s starlight. These bands reveal the compositions and ages of the stars, and also the distance of the galaxy. Credit: P. Van Dokkum, R. Abraham, J. Brodie