primary rainbow

primary rainbow

[′prī‚mer·ē ′rān‚bō]
(optics)
The most common of the principal rainbow phenomena, which appears as an arc of angular radius of about 42° about the observer's antisolar point; it is the inner of two rainbows, whose light undergoes only one internal reflection, and which is narrower and brighter than the outer, or secondary, rainbow.
References in periodicals archive ?
When a drop is flattened, its primary rainbow is flattened as well (Venturi 1814; Brandes 1816; Mobius 1910).
Happily, Judy hops into bed at home, anticipating "another busy day full of Mystery, Adventure, and People Who Need Her!" Every page of "Judy Hopps and the Missing Jumbo-Pop" is splashed with primary rainbow colored portraits of the animal denizens of Zootopia, busily leading their daily lives in perfect synchronicity with (other) parallel worlds.
In a so-called primary rainbow - the lowest and also normally the brightest rainbow - the arc of a rainbow shows red on the outer or upper part of the arc and violet on the inner section.
"In the case of a secondary rainbow, you'd still have the primary rainbow -- you'd have that first reflection at 42 degrees.
A primary rainbow is the rainbow you see when you have your back to the sun.
In primary rainbow trout hepatocytes, exposure to cadmium results in DNA fragmentation and activation of caspases 3, 8, and 9, hallmarks of apoptosis (Risso-de Faverney et al., 2001; Risso-de Faverney et al., 2004).
The primary rainbow is produced by light that undergoes a single reflection inside each raindrop before emerging.
After a rain shower, with a moderately low Sun shining behind your back, you might see a primary rainbow appear as a bright arc 42[degrees] from the shadow of your head.
A twinned rainbow looks like a primary rainbow with another primary rainbow bulging out for a section of its arc just above the first.
The band of the primary rainbow is about three times as wide as the Moon in apparent size, so there's room to spare.
These arcs are called the "supernumerary bows." Supernumerary means "extra," and the label was applied at a time when the prevalent rainbow theory couldn't explain the existence of the colored bands lying outside the primary rainbow's spectrum.
The Met Office says: "This means the sequence of colours is inverted compared to the primary rainbow, with the secondary bow appearing about 10 degrees above the primary bow."