Portal:Radiation astronomy

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Radiation astronomy
This image is a composite of several types of radiation astronomy: radio, infrared, visual, ultraviolet, soft and hard X-ray. Credit: NASA.

Radiation astronomy is astronomy applied to the various extraterrestrial sources of radiation, especially at night. It is also conducted above the Earth's atmosphere and at locations away from the Earth, by satellites and space probes, as a part of explorational (or exploratory) radiation astronomy.

Seeing the Sun and feeling the warmth of its rays is probably a student's first encounter with an astronomical radiation source. This will happen from a very early age, but a first understanding of the concepts of radiation may occur at a secondary educational level.

Radiation is all around us on top of the Earth's crust, regolith, and soil, where we live. The study of radiation, including radiation astronomy, usually intensifies at the university undergraduate level.

And, generally, radiation becomes hazardous, when a student embarks on graduate study.

Cautionary speculation may be introduced unexpectedly to stimulate the imagination and open a small crack in a few doors that may appear closed at present. As such, this learning resource incorporates some state-of-the-art results from the scholarly literature.

The laboratories of radiation astronomy are limited to the radiation observatories themselves and the computers and other instruments (sometimes off site) used to analyze the results.

Selected radiation astronomy

Astronomy that benefits from the detection of mesons, directly or indirectly, is meson astronomy.

For antiproton-proton annihilation at rest, a meson result is, for example,

Selected lecture

Radiation astronomy sources

Volcanic bombs are thrown into the sky and travel some distance before returning to the ground. This bomb is in the Craters of the Moon National Monument and Preserve, Idaho, USA. Credit: National Park Service.

In source astronomy, the question is "Where did it come from?"

Source astronomy has its origins in the actions of intelligent life on Earth when they noticed things or entities falling from above and became aware of the sky. Sometimes what they noticed is an acorn or walnut being dropped on them or thrown at them by a squirrel in a tree. Other events coupled with keen intellect allowed these life forms to deduce that some entities falling from the sky are coming down from locations higher than the tops of local trees.

Def. a source or apparent source detected or “created at or near the time of the [ event or] events”[1] is called a primary source.

Direct observation and tracking of the origination and trajectories of falling entities such as volcanic bombs presented early intelligent life with vital albeit sometimes dangerous opportunities to compose the science that led to source astronomy.


  1. primary source. San Francisco, California: Wikimedia Foundation, Inc. February 16, 2012. Retrieved 2012-07-14.
Selected theory

Mathematical radiation astronomy

This animation depicts the collision between our Milky Way galaxy and the Andromeda galaxy. Credit: Visualization Credit: NASA; ESA; and F. Summers, STScI; Simulation Credit: NASA; ESA; G. Besla, Columbia University; and R. van der Marel, STScI.

Most of the mathematics needed to understand the information acquired through astronomical radiation observation comes from physics. But, there are special needs for situations that intertwine mathematics with phenomena that may not yet have sufficient physics to explain the observations. Both uses constitute radiation mathematics, or astronomical radiation mathematics, or a portion of mathematical radiation astronomy.

Astronomical radiation mathematics is the laboratory mathematics such as simulations that are generated to try to understand the observations of radiation astronomy.

The mathematics needed to understand radiation astronomy starts with arithmetic and often needs various topics in calculus and differential equations to produce likely models.

Selected topic


The 15" refractor at Comanche Springs Astronomy Campus had its finder scope (a Stellarvue 80/9D achromat) equipped with a Baader Herschel Solar Wedge and a Solar Continuum Filter for today's transit of Venus. Credit: Jeff Barton from Richardson, TX, USA.{{free media}}

Lyc photon or Ly continuum photon or Lyman continuum photon are a kind of photon emitted from stars. Hydrogen is ionized by absorption of Lyc photons. Lyc photons are in the ultraviolet portion of the electromagnetic spectrum of the hydrogen atom and immediately next to the limit of the Lyman series of the spectrum with wavelengths that are shorter than 91.1267 nanometres and with energy above 13.6 eV.

Selected X-ray astronomy article
This X-ray Landmarks frame highlights a variety of X-ray objects, including X-ray binaries, supernova remnants, and active galaxies. The rectangular image is a magnification of the center of our Milky Way galaxy, which has a high density of X-ray stars. The Crab Nebula is in Taurus at ~RA 05h Dec 22°. The Large Magellanic Cloud is at ~RA 05h Dec -70° in Mensa\Dorado. NGC 4151 is in Canes Venatici at ~+RA 12h Dec +39°. Scorpius X-1 is at ~RA 16h Dec -15°. The center of the Milky Way in the frame is at ~RA 17h Dec -29°. Cygnus X-1 is at ~RA 20h Dec +35°. Cassiopeia A is at ~RA 23h Dec +58°. The point of view of the frame is in plane of the galaxy, at the 98° point looking edge on at the galaxy.

There are 88 official constellations that the International Astronomical Union (IAU) has used to divide the celestial sphere into 89 irregularly shaped boxes. The constellation Serpens is split into two separate sections, Serpens Caput (the snake's head) to the west and Serpens Cauda (the snake's tail) to the east. Using detectors placed above the Earth's atmosphere, X-radiation has been detected as incoming from each of these constellational areas. Searching for the first X-ray source per constellation is a history of science exercise that is still ongoing as the initial X-ray source for many of the constellations is questionable or unknown.

Selected image
Messier 74 ULX.jpg

This is a composite image (X-ray - red, optical - blue & white) of the spiral galaxy M74 with an ultraluminous X-ray source (ULX) indicated inside the box. Image is 9 arcmin per side at RA 01h 36m 41.70s Dec +15° 46' 59.0" in Pisces. Observation dates: June 19, 2001; October 19, 2001. Aka: NGC 628, ULX: CXOU J013651.1+154547. Credit: X-ray; J. Liu (U.Mich.) et al., CXC, NASA - Optical; Todd Boroson/NOAO/AURA/NSF.{{Fair use}}

Selected lesson

First cyan source in Caelum

This is an image of NGC 1679 in Caelum. It is a spiral galaxy located two degrees south of Zeta Caeli. Credit: NASA/ESA (Wikisky).

The first cyan source in Caelum is unknown.

This is a lesson in map reading, coordinate matching, and searching. It is also a project in the history of cyan astronomy looking for the first astronomical cyan source discovered in the constellation of Caelum.

Nearly all the background you need to participate and learn by doing you've probably already been introduced to at a secondary level.

Some of the material and information is at the college or university level, and as you progress in finding cyan sources, you'll run into concepts and experimental tests that are an actual search.

To succeed in finding a cyan source in Caelum is the first step. Next, you'll need to determine the time stamp of its discovery and compare it with any that have already been found. Over the history of cyan astronomy a number of sources have been found, many as point sources in the night sky. These points are located on the celestial sphere using coordinate systems. Familiarity with these coordinate systems is not a prerequisite. Here the challenge is geometrical, astrophysical, and historical.

NGC 1679 in the image at left appears to contain some cyan, probably as a result of a mixture of light blue and yellow.

Selected quiz

Blue astronomy quiz

This is a detailed, photo-like view of Earth based largely on observations from the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite. Credit: Robert Simmon and Marit Jentoft-Nilsen, NASA.

Blue astronomy is a lecture from the radiation astronomy department for the course on the principles of radiation astronomy.

You are free to take this quiz based on blue astronomy at any time.

To improve your scores, read and study the lecture, the links contained within, listed under See also, External links, and in the {{principles of radiation astronomy}} template. This should give you adequate background to get 100 %.

As a "learning by doing" resource, this quiz helps you to assess your knowledge and understanding of the information, and it is a quiz you may take over and over as a learning resource to improve your knowledge, understanding, test-taking skills, and your score.

Suggestion: Have the lecture available in a separate window.

To master the information and use only your memory while taking the quiz, try rewriting the information from more familiar points of view, or be creative with association.

Enjoy learning by doing!

Selected laboratory

Cratering astronomy laboratory

The crater in Santa Ana Volcano is photographed from a United States Air Force C-130 Hercules flying above El Salvador. Credit: José Fernández, U.S Air Force.

This laboratory is an activity for you to create or analyze a cratering. While it is part of the astronomy course principles of radiation astronomy, it is also independent.

Some suggested types of cratering to consider include a lightning strike, a bullet shot into some material, a water droplet hitting the surface of a beaker of water, a subterranean explosion, a sand vortex, or a meteorite impact.

More importantly, there is your cratering idea. And, yes, you can crater a peanut butter and jelly sandwich if you wish to.

Okay, this is an astronomy cratering laboratory, but you may create what a crater is. Another example is a volcanic crater.

I will provide an example of a cratering experiment. The rest is up to you.

Please put any questions you may have, and your laboratory results, you'd like evaluated, on the laboratory's discussion page.

Enjoy learning by doing!

Selected problems

Angular momentum and energy

This diagram describes the relationship between force (F), torque (τ), momentum (p), and angular momentum (L) vectors in a rotating system. 'r' is the radius. Credit: Yawe.

Angular momentum and energy are concepts developed to try to understand everyday reality.

An angular momentum L of a particle about an origin is given by

where r is the radius vector of the particle relative to the origin, p is the linear momentum of the particle, and × denotes the cross product (r · p sin θ). Theta is the angle between r and p.

Please put any questions you may have, and your results, you'd like evaluated, on the problem set's discussion page.

Enjoy learning by doing!

Selected X-ray astronomy pictures
Ms0735 xray 420.jpg

Chandra X-ray Observatory image of the hot X-ray emitting gas that pervades the galaxy cluster MS 0735.6+7421 in the constellation Camelopardalis. Two vast cavities - each 600,000 lyrs in diameter appear on opposite sides of a large galaxy at the center of the cluster. These cavities are filled with a two-sided, elongated, magnetized bubble of extremely high-energy electrons that emit radio waves. Image is 4.2 arcmin per side. RA 07h 41m 50.20s Dec +74° 14' 51.00". Observation date: November 30, 2003. Credit: NASA/CXC/Ohio U./B.McNamara.

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