)
Light curve of Mira
Mira
orMira Ceti
(mÿ -ră, meer -ă see -tÿ, set -ee) (the Wonderful; ō Cet) A red giant in the constellation Cetus that is a long-period variable star with an average period of 331 days. It was known to early astronomers for its regular appearances and disappearances and was established in 1638 as a variable star. It is the prototype of the Mira stars. Its radius varies by 20 per cent during its cycle and at maximum size and brightness is over 330 times the Sun's radius. The surface temperature varies from about 2600 K at maximum luminosity down to about 1900 K. The visible light emitted varies considerably, usually by about 6 magnitudes, over the cycle (see illustration). The average maximum apparent magnitude, m V, lies between 3 and 4 although it may reach 2nd magnitude. At minimum it is about 8th to 10th magnitude. Mira is also an infrared source, the emission arising from dust grains in the expanding envelope of gas.Mira is both a visual binary with a faint peculiar companion that is also variable, and an optical double. MV : –1.0 (var.); spectral type: M6e–M9e III; distance: 40 pc.
Collins Dictionary of Astronomy © Market House Books Ltd, 2006
Mira
[′mir·ə] (astronomy)
The first star recognized to be a periodic variable; has a period of 332 ± 9 days and its spectrum changes from M5e at maximum to M9e at minimum;it is the prototype of long-period variable stars.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
Smart Display
(1) A table top device with a virtual assistant and screen. The Echo Show, Echo Spot, Google Nest Hub and Facebook Portal are examples. See Amazon Echo, Google Nest and Facebook Portal.(2) A table top Android tablet from ViewSonic that also serves as a 21.5" touchscreen monitor for a desktop or laptop computer via HDMI.
(3) (Smart Display) An earlier thin client from Microsoft that functioned as a remote terminal to a Windows XP PC via Wi-Fi. It also served as a regular monitor. Code-named "Mira" (Spanish for "look") and available with 10" or 15" screens, it ran Windows CE for Smart Display OS and used Remote Desktop to connect. Introduced in 2003, the costly unit was discontinued soon after because it was not popular. LCD monitor prices were dropping, and the XP machine could not be used at the same time. See thin client and Remote Desktop Services.
Copyright © 1981-2025 by The Computer Language Company Inc. All Rights reserved. THIS DEFINITION IS FOR PERSONAL USE ONLY. All other reproduction is strictly prohibited without permission from the publisher.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.
Mira
(o Ceti), the first known variable star; discovered as a variable star in 1596 by D. Fabricius. Mira varies in brightness from a stellar magnitude of 2.0 to a stellar magnitude of 10.1, with a period averaging 331.5 days. The variations in brightness are due to the pulsations of the star, as a result of which the diameter varies by approximately 10 percent, which is accompanied by a variation in the temperature and brightness of the star’s surface. Mira measures about 500 million km in diameter and is located 77 parsecs from the sun.
The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.