Archive for the ‘Infrared Astronomy’ Category

07/08/2019 – Ephemeris – The bright star Vega

July 8, 2019 Comments off

Ephemeris for Monday, July 8th. Today the Sun will be up for 15 hours and 24 minutes, setting at 9:29, and it will rise tomorrow at 6:06. The Moon, 1 day before first quarter, will set at 1:31 tomorrow morning.

The bright star high in the east is Vega, one of the stars of the Summer Triangle an informal constellation called an asterism. Vega belongs to the official constellation Lyra the harp, which includes a narrow parallelogram of stars to its south. Vega is regarded by astronomers as a standard calibration star. Though a first magnitude star, its actual magnitude is 0.03. It is a type A0 a pure white star, and is 25 light years away. Astronomers however got a shock in 1983 when calibrating the Infrared Astronomy Satellite (IRAS) on it: Vega showed an excess of Infrared radiation which means the star is orbited by a disk of dust, perhaps a Kuiper belt of its own. Due to the slow wobble of the earth’s axis Vega will become our pole star in about 14 thousand years.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.


The Summer Triangle July 5, 2012 at 11 p.m. Created using Stellaruim and The Gimp.

The Summer Triangle. Created using Stellarium.

Vega - Alpha Lyrae

Vega: Comparison to the Sun and its dust ring. Credit Orange County Astronomers.

06/24/2013 – Ephemeris – Infrared astronomy

June 24, 2013 Comments off

Ephemeris for Monday, June 24th.  Today the sun will be up for 15 hours and 33 minutes, setting at 9:31.   The moon, 1 day past full, will rise at 10:27 this evening.  Tomorrow the sun will rise at 5:58.

During most of history astronomers viewed the heavens in visible light.  That’s all we had, our eyes, later augmented by telescopes, and photography.  Today astronomers view the heavens with a myriad of detectors on the earth, above the earth and inside the earth.  Radiation detected, beside visible are radio, infrared, ultraviolet, x-rays, and gamma rays, all part of the electromagnetic spectrum as is visible light.  Besides that the observe neutrinos and cosmic rays, and are searching for gravitational waves.  An intense field of study now is infrared, which must be observed from high mountaintops or from space.  Last year I visited one of those facilities at nearly 14,000 feet altitude the observatories atop Mauna Kea in Hawaii. [Which included the two largest telescopes in the world the twin 10 meter Keck telescopes, Gemini North, Subaru and other telescopes. ]

Times are for the Traverse City/Interlochen area of Michigan.  They may be different for your location.


Keck Observatory

The twin domes of the Keck 10 meter telescopes. Left is the Japanese Subaru telescope. Right is the NASA Infrared Telescope facility. Credit: Bob Moler.  Click to enlarge.

Gemini North

The 8.1 meter Gemini North telescope dome in the center. To the left is the Canada-France-Hawaii Telescope dome. Credit: Bob Moler.