Navy+Prototype+OpticalInterferometer+(NPOI)

= = = = =Navy Precision Optical Interferometer ([|NPOI])=

From the highest angular resolution Ha observations to date, NPOI found the **Be stars g Cas and f Per** to have circum-stellar emission consistent with a Gaussian intensity distribution rather than a uniform disk or ring-like structure.

In 2002, NPOI accomplished **the first 6-telescope image** by O/IR interferometry, producing an image of the triple system h Vir.

NPOI observations show that **Vega is a pole-on rapid rotator** spinning at 93% of its breakup speed, with more than 2400 K difference in temp-erature from pole to equator. The temperature variation accounts for Vega’s near-IR excess and explains why no single atmospheric model accounts for its spectrum.