Ascientist studying stars can estimate the
temperatures of stars by their

They observe very closely using telescopes and also split the light into its constituent colors (or frequencies) using a device called a diffraction grating.

By noting the wavelength at which the radiation emitted by the star.

b would be the right answer

answer : haversian

[explanation: -(compact bone is organized as parallel columns, known as haversian systems, which run lengthwise down the axis of long bones. these columns are composed of lamellae, concentric rings of bone, surrounding a central channel, or haversian canal, that contains the nerves, blood vessels, and lymphatic system of the bone)]