Often there is also a broad but shallow absorption feature centered near 0.63 m.

M detected absorption features near 2.8-3.0 m on the surface of the Moon.

There are no absorption features of mafic minerals found.

No absorption features were detected in the whole wavelength range covered by observations-0.4-3.5 μm.

In the part of the infrared spectrum near 3.4 microns, three distinct absorption features are seen.

These separated absorption features allow for the monitoring of valence electrons in each distinct nanotube.

There is a broad absorption feature near 2 μm possible belonging to water ice or some water-altered material.

There is also a weak absorption feature near the wavelength of 2 μm, probably caused by water-ice.

If this bandwidth is comparable to the width of the absorption features, then the measured extinction coefficient will be altered.

Spectroscopy shows narrow, time-varying absorption features being caused by circumstellar gas moving toward the star.