Open main menu

Wikiversity β

Radiation astronomy/First orange source in Cancer

< Radiation astronomy
Cloud bands are clearly visible on Jupiter. Credit: NASA/JPL/USGS.

The first orange source in Cancer is unknown.

This is a lesson in map reading, coordinate matching, and researching. It is also a research project in the history of orange astronomy looking for the first astronomical orange source discovered in the constellation of Cancer.

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 orange sources, you'll run into concepts and experimental tests that are actual research.

To succeed in finding an orange source in Cancer 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 orange 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.


Control groupsEdit

Main source: Control groups

What would be a control group to compare astronomical orange sources to?

Astronomical orange sourcesEdit

This brown dwarf (smaller object) orbits the star Gliese 229, which is located in the constellation Lepus about 19 light years from Earth. The brown dwarf, called Gliese 229B, is about 20 to 50 times the mass of Jupiter. Credit: .

Brown dwarfs are sub-stellar objects that have fully convective surfaces and interiors, with no chemical differentiation by depth. Brown dwarfs occupy the mass range between that of large gas giant planets and the lowest-mass stars; this upper limit is between 75[1] and 80 Jupiter masses ( ).

Astronomers have reported that spectral class T brown dwarves (the ones with the coolest temperatures) are colored magenta because of absorption by sodium and potassium atoms of light in the green portion of the spectrum.[1][2][3]

First sourcesEdit

The "earliest known astronomy anywhere in the world [is] that of the Australian Aborigines, whose culture has existed for some 40,000 years".[4]

"The Aranda tribes of Central Australia, for example, distinguish red stars from white, blue and yellow stars."[4]


To introduce yourself to some aspects of the challenge may I suggest reading the highlighted links mentioned above, and if you're curious, those listed under the section "See also" below.

Orange rays are a form of radiation that is currently part of the electromagnetic radiation intersecting the Earth. More information about the radiation of astronomy is in radiation astronomy.


This is an image of the International Astronomical Union (IAU) sky map of the constellation Cancer. Credit: IAU and Roger Sinnott & Rick Fienberg, Sky & Telescope magazine.
Heracles is attacked by Karkinos (bottom) and the Lernaean Hydra, under the aid of Athena on white-ground Ancient Greek Attic lekythos, ca. 500–475 BC. Louvre Museum, Paris. Credit: Bibi Saint-Pol.

The Wikipedia article about the constellation Cancer contains a high school level description. The figure at right shows the sky map of Cancer. Around the edges of the map are coordinates related to longitude and latitude, but with the Earth rotating on its axis every 24 hours the celestial coordinates must remain fixed. How has this been accomplished?

Also, in the Wikipedia article is a list of stars in Cancer. What's the difference between a star and an astronomical orange source?

From the Wikipedia article on the Zodiac, is Cancer a zodiacal constellation?

Cancer is said to have been the place for the Akkadian Sun of the South.

Testing a sourceEdit

There are many web sites that may have an orange source listed for the constellation Cancer.

Zodiacal sourcesEdit

Reading the learning resource orange astronomy, are any zodiacal astronomical orange sources described?

To evaluate a possible orange zodiacal source, skip ahead to the section "Orange sources".

Wikipedia sourcesEdit

A. Constellation article

Search the constellation article with "orange" to find any possible astronomical orange sources mentioned. If any are mentioned, skip ahead to the section "Orange sources".

Under "Notable features" in the Wikipedia article on the constellation Cancer is the list of stars in Cancer. Click on this link.

Using the following color (temperature) classification of stars, starting perhaps with Alpha Cancer, or α Cnc, look for orange-hued stars.

Class Temperature[5]
Conventional color Apparent color[6][7][8] Mass[5]
(solar masses, Mʘ)
(solar radii, Rʘ)
(bolometric, Lʘ)
Fraction of all
main sequence stars[9]
O ≥ 33,000 K blue blue ≥ 16 ≥ 6.6 ≥ 30,000 Weak ~0.00003%
B 10,000–33,000 K blue to blue white blue white 2.1–16 1.8–6.6 25–30,000 Medium 0.13%
A 7,500–10,000 K white white to blue white 1.4–2.1 1.4–1.8 5–25 Strong 0.6%
F 6,000–7,500 K yellowish white white 1.04–1.4 1.15–1.4 1.5–5 Medium 3%
G 5,200–6,000 K yellow yellowish white 0.8–1.04 0.96–1.15 0.6–1.5 Weak 7.6%
K 3,700–5,200 K orange yellow orange 0.45–0.8 0.7–0.96 0.08–0.6 Very weak 12.1%
M ≤ 3,700 K red orange red ≤ 0.45 ≤ 0.7 ≤ 0.08 Very weak 76.45%.

In the list of stars in Cancer, under "Sp. class", is beta Cancri. or β Cnc.

To the right of β Cnc are coordinates:

  1. [Right ascension] (RA): 08h 16m 30.95s and
  2. [Declination] (Dec): +09° 11' 08.4".

Find these coordinates on the Cancer map at the right. Is beta Cancer really inside the boundaries of the constellation?

To evaluate the star as an orange source, skip ahead to the section "Orange sources".

B. Wikipedia search

Another way to look for orange sources in the constellation is to perform a search on Wikipedia. Try "Cancer orange" without the quotes. This yields 2,240 possible astronomical orange source candidates.

To evaluate an orange source, skip ahead to section "Orange sources".

SIMBAD sourcesEdit

Another way to find possible orange sources in Cancer is to use search queries on SIMBAD.

Click on the SIMBAD link under "External links" below, then click on "Criteria query" or "by criteria".

In the tan box, type in "region(08 58 29.20 +11 51 28.0, 10m)", without the quotes. This tells the SIMBAD computer you are interested in a circular region of the celestial sphere centered on the coordinates for alpha Cancer, with a radius of 10 arcminutes (m).

Notice on the page over at the right from the tan colored box: "Return". The default is "object count". Click on "submit query". In a few moments a result something like "Number of objects: 13" should appear. Click "Back" to see the tan box again.

To see if you have found at least one object, change "Return" to "display" by clicking on the circle to its left, then "submit query".

SIMBAD should display a list of objects. Read through the resource orange astronomy for clues that may indicate whether a particular spectral type (Sp type) is an orange source. If none of the objects listed seems to be described as an orange source, try going "Back" and increasing the arcminutes from "10m" to "20m", and repeat until an orange source is found.

Once you believe you have discovered an orange source, proceed to the section "Orange sources".

Orange sourcesEdit

There are several ways to evaluate an orange source for the constellation Cancer.

Zodiacal orange sourcesEdit

In historical astronomy, the zodiac (Greek: ζῳδιακός, zōidiakos) is a circle of twelve 30° divisions of celestial longitude that are centered upon the ecliptic: the apparent path of the Sun across the celestial sphere over the course of the year. The paths of the Moon and visible planets also remain close to the ecliptic, within the belt of the zodiac, which extends 8-9° north or south of the ecliptic, as measured in celestial latitude. Historically, these twelve divisions are called signs. Essentially, the zodiac is a celestial coordinate system, or more specifically an ecliptic coordinate system, which takes the ecliptic as the origin of latitude, and the position of the Sun at vernal equinox as the origin of longitude.

The Sun is apparently within the constellation Cancer between July 20 and August 10, 2011.

Jupiter is an astronomical orange source. When is Jupiter in the constellation Cancer? "Jupiter ... is the ruling planet of Sagittarius and is exalted in Cancer. ... Jupiter takes 11.9 years to orbit the Sun, spending almost an earth year (361 days) in each sign of the zodiac. Astrologically speaking, using Eastern Standard Time in the United States, on "July 12, 2001 8:03 PM Jupiter enters Cancer ... Aug 1, 2002 1:20 PM Jupiter enters Leo".[10] Even though the astrological constellations are not exactly the same as the modern astronomical ones, from about mid-July, 2001, until near the end of July 2002, Jupiter is in Cancer, and will not be in Cancer again until 2013. But, when did the color orange, or brown, become associated with Jupiter?

Titan is an orange source in orbit around Saturn. When is Titan in Cancer? Saturn takes 29.5 years to orbit the Sun, spending about 2.46 years in each sign of the zodiac.

Uranus may be viewed by the Hubble Space Telescope at 619.0 nm, making Uranus when so viewed an astronomical orange source. When is Uranus in Cancer? Uranus takes 84 years to orbit the Sun, spending about 7 years in each sign of the zodiac. Uranus was discovered only in 1781 by Sir William Herschel. When is the earliest observation of Uranus in the orange band?

Wikipedia orange sourcesEdit

A. Constellation article From the constellation entry there is

  1. β Cnc (Altarf) is the brightest star in Cancer at magnitude 3.5. It is an orange-hued binary star system consisting of a K-type orange giant and a red dwarf located 290 light-years from Earth.
  2. δ Cnc (Asellus Australis) is an orange-hued giant star of magnitude 3.9, 136 light-years from Earth.

B. List of stars article

  1. The list of stars in Cancer begins with β Cnc.
  2. The second entry is δ Cnc.

C. Wikipedia search A search of Wikipedia using "Cancer orange" without the quotes yields

  1. HIP 40484 is an orange giant star in the constellation of Cancer.
  2. 60 Cancri is a star in the constellation Cancer. 60 Cancri is an orange K-type giant with an apparent magnitude of +5.44.

SIMBAD orange sourcesEdit

To check any source (even one from Wikipedia) on SIMBAD, click of the "External link" to the "SIMBAD Astronomical Database".

At the lower right side of the SIMBAD Astronomical Database page is a "Basic search" box. There are several ways to try your target:

  1. source name: without the quotes or
  2. source coordinates: without the quotes, for example, "08 58 29.20 +11 51 28.0".

If you are looking at a SIMBAD generated table which lists possible targets, click on one.

On its SIMBAD page move over to the right side until you see an Aladin visual photograph of the object. Is it an orange source?

Even if the source does not look orange, look down the left hand side of the page for "Spectral type:". From your reading of orange astronomy, do you believe the source is an orange source, or not? Noting that SIMBAD does, or does not consider the source to be an orange source is important, so skip down to the "SIMBAD time stamp" section.

If you have already found an orange source (or a table of them) using SIMBAD, click on the blue link identifier for the first.

A region(08 58 29.20 +11 51 28.0,40m) search on SIMBAD shows HD 76524 is a spectral type K0 star.

SIMBAD time stampEdit

Peruse the SIMBAD page for a time stamp or date of last revision. [Hint: it may look something like "2012.01.09CET20:10:02" and be in the upper right.]

If the entry at SIMBAD convinces you that the source is not an orange source, edit the "Non-orange sources in Cancer" section near the bottom of this page and type in an entry similar to "# Source Name 2012.01.09CET20:10:02 SIMBAD article "SIMBAD source name".", without the first set of quotes, followed by four ~s.

If your SIMBAD analysis convinces you that you have found an orange source in Cancer (did you check the coordinates vs. the map of Cancer?), make an entry something like the ones in the section "Orange sources in Cancer".

Challenging an entryEdit

Any entry in either the section "Orange sources in Cancer" or "Non-orange sources in Cancer" can be challenged. The time stamp may be challenged to see if there is an earlier one. The source may be challenged by an earlier source.

Zodiacal challengeEdit

The difficulty here is finding a primary source that verifies when Jupiter is in the astronomical constellation Cancer. Secondly, how far back in time is Jupiter referred to as an orange or brown source?

Wikipedia challengeEdit

Is Wikipedia a 'primary source', or does the Wikipedia article cite a source?

Even though Wikipedia has an article on the source, is it a good place to stop in testing whether the source has been detected as an astronomical orange source?

If the Wikipedia article cites a primary source, skip down to the section on "Primary sources".

SIMBAD challengeEdit

Is SIMBAD a 'primary source'?

SIMBAD is an astronomical database provided by the Centre de Données astronomiques de Strasbourg. It is an authoritative source, but they do occasionally make a mistake.

If you find an orange source within the constellation on SIMBAD, the next step is to find the earliest time stamp of discovery.

Primary sourcesEdit

Primary sources may be searched for possible additional information perhaps not yet evaluated by SIMBAD or not presented in a Wikipedia article about a source.

Zodiacal test sourceEdit

If the zodiacal source is Wikipedia, skip to the next section. If the zodiacal source is a web source, try one of the External links listed near the bottom of this lesson such as "Google scholar Advanced Scholar Search". A suggested search may include "Jupiter" and "Cancer".

Wikipedia test sourceEdit

For a Wikipedia article that cites a primary source, scroll down to the reference and open the reference. Read through the article looking for where the source mentioned in the Wikipedia article occurs. Some primary source authors may use source designations that are not mentioned in the Wikipedia article. To look for other designations, click on the link to SIMBAD in the "External links" on this page, enter the source name from the Wikipedia article, and see if other names are mentioned in the article.

When none of the names are mentioned, click on the link for "Google Advanced Search" in the list of "External links", enter the source name or designation(s) such as "Gliese 866", with "orange" to see if the source has a reference indicating it is an orange source. And, look for the earliest one. Compose an entry using the primary source.

SIMBAD test sourceEdit

Further down the SIMBAD page is a list of "Identifiers". Click on the blue bold portion.

On the page that appears, there should be a primary source listed after Ref:. Click on the blue link with the oldest year. This yields an earlier time stamp and entry citation like the current one in the section "Orange sources in Cancer". If you find another source or an earlier time stamp, compose a similar entry and edit the section. Additional information to add into the reference can be found by clicking on "ADS services" from the SIMBAD page.

Changing an entryEdit

From your analysis of the source so far, is it an orange source?

If you have found an earlier time stamp for the source than the one listed in the section below "Non-orange sources in Cancer" and the answer to the above question is "no", you can edit the section with your result. Or, you can leave the entries as is and try another star or object.

If you have found an earlier time stamp for a source than the one listed in the section below "Orange sources in Cancer", edit the section with your result. Or, if you found another orange source with a comparable or earlier time stamp, edit the section with your result.

Orange sources in CancerEdit

  1. Jupiter. "From col. iv, lines 2-3, we have Saturn in Pisces and Jupiter in Cancer on August 1. Tuckerman's tablesd show that this configuration occurred in A.D. 21-22, and thereafter at intervals of roughly 59 years."[11] --Marshallsumter (talk) 20:42, 20 August 2012 (UTC)
  2. Jupiter and Titan. "The conjunction of Jupiter and Saturn in Cancer was an unusual astronomical event which had not occurred since 769."[12] --Marshallsumter (talk) 20:05, 20 August 2012 (UTC)
  3. Jupiter and Titan. "The point of exact conjunction was, as we have seen, not in Cancer, though within a few degrees of its border; but, according to the older use of the term, Saturn and Jupiter were in conjunction in Cancer in latter May and June of 1385."[13] --Marshallsumter (talk) 20:05, 20 August 2012 (UTC)
  4. Jupiter. Astrologically speaking, using Eastern Standard Time in the United States, on "July 12, 2001 8:03 PM Jupiter enters Cancer ... Aug 1, 2002 1:20 PM Jupiter enters Leo".[10] --Marshallsumter (talk) 10:12, 20 August 2012 (UTC)
  5. β Cnc is an orange-hued binary star system consisting of a K-type orange giant and a red dwarf. This page was last modified on 15 August 2012 at 16:37. Beta Cancri is spectral class K4III. This page was last modified on 15 August 2012 at 14:50. --Marshallsumter (talk) 18:12, 20 August 2012 (UTC)
  6. δ Cnc is an orange-hued giant star. This page was last modified on 15 August 2012 at 16:37. Delta Cancri is spectral class K0III. This page was last modified on 15 August 2012 at 14:50. --Marshallsumter (talk) 18:12, 20 August 2012 (UTC)
  7. HIP 40484 is an orange giant star in the constellation of Cancer. Its spectral type is K0. This page was last modified on 21 March 2012 at 15:00. --Marshallsumter (talk) 18:12, 20 August 2012 (UTC)
  8. 60 Cancri is a star in the constellation Cancer. 60 Cancri is an orange K-type giant of spectral type gK5. This page was last modified on 9 August 2012 at 23:19. --Marshallsumter (talk) 18:12, 20 August 2012 (UTC)
  9. HD 76524 2012.08.20CEST20:14:44 SIMBAD "HD 76524". The visual image of the star shows it to be an orange-hued star. --Marshallsumter (talk) 18:22, 20 August 2012 (UTC)

Non-orange sources in CancerEdit

Oldest recordsEdit

Main sources: Records/Oldest and Oldest records
  1. Jupiter. "From col. iv, lines 2-3, we have Saturn in Pisces and Jupiter in Cancer on August 1. Tuckerman's tablesd show that this configuration occurred in A.D. 21-22, and thereafter at intervals of roughly 59 years."[11]


Main source: Hypotheses
  1. The first orange source in Cancer may have been observed around 42,000 b2k.

See alsoEdit


  1. Brown Dwarves (go halfway down the website to see a picture of a magenta brown dwarf):
  2. Burrows et al. The theory of brown dwarfs and extrasolar giant planets. Reviews of Modern Physics 2001; 73: 719-65
  3. "An Artist's View of Brown Dwarf Types" Dr. Robert Hurt of the Infrared Processing and Analysis Center
  4. 4.0 4.1 R Haynes (June 27, 1996). Raymond Haynes, Roslynn Haynes, David Malin & Richard McGee. ed. Explorers of the southern sky: a history of Australian astronomy. The Pitt Building, Trumpington Stree, Cambridge CB2 1RP, England UK: Cambridge University Press. pp. 527. ISBN 0521365759. Retrieved 2013-08-02. 
  5. 5.0 5.1 5.2 5.3 Tables VII, VIII, Empirical bolometric corrections for the main-sequence, G. M. H. J. Habets and J. R. W. Heinze, Astronomy and Astrophysics Supplement Series 46 (November 1981), pp. 193–237, bibcode=1981A&AS...46..193H. Luminosities are derived from Mbol figures, using Mbol(ʘ)=4.75.
  6. The Guinness book of astronomy facts & feats, Patrick Moore, 1992, 0-900424-76-1
  7. The Colour of Stars. Australia Telescope Outreach and Education. 2004-12-21. Retrieved 2007-09-26.  — Explains the reason for the difference in color perception.
  8. What color are the stars?, Mitchell Charity. Accessed online March 19, 2008.
  9. Glenn LeDrew (February 2001). "The Real Starry Sky". Journal of the Royal Astronomical Society of Canada 95 (1 (whole No. 686, February 2001), pp. 32–33. Note: Table 2 has an error and so this article will use 824 as the assumed correct total of main-sequence stars). 
  10. 10.0 10.1 Molly Hall (2012). Jupiter Sign Tables 1930 to 2014. New York: Astrology. Retrieved 2012-08-19. 
  11. 11.0 11.1 Alexander Jones (1994). "An Astronomical Ephemeris for A.D. 140:P. Harris I.60". Zeitschrift für Papyrologie und Epigraphik 100: 59-63. Retrieved 2012-08-20. 
  12. John J. O'Connor (October 1956). "The Astronomical Dating of Chaucer's" Troilus"". The Journal of English and Germanic Philology 55 (4): 556-62. Retrieved 2012-08-20. 
  13. Robert Kilburn Root, Henry Norris Russell (March 1924). "A Planetary Date for Chaucer's Troillus". Publications of the Modern Language Association of America (PMLA) 39 (1): 48-63. Retrieved 2012-08-20. 

External linksEdit