Heavenly G Asterism Indents Rather Than Encircles Betelgeuse

Summary: The Heavenly G asterism indents rather than encircles Betelgeuse in a refashioning of the Winter Hexagon asterism.

Betelgeuse in Orion the Hunter constellation holds the place of honor in the Heavenly G asterism as the celestial letter’s final lobe; nebulas of the Orion Molecular Cloud complex surround Constellation Orion with Heavenly G participants’ red Betelgeuse (upper left) and bluish-white Rigel (lower right); Thursday, Aug. 23, 2012: Rogelio Bernal Andreo, CC BY SA 3.0 Unported, via Wikimedia Commons

The Heavenly G asterism indents rather than encircles Betelgeuse as the celestial letter refashions the Winter Hexagon asterism.

Canadian comet and minor planet discoverer David H. Levy (born May 22, 1948) describes the Heavenly G asterism in his bestselling guide to the night sky, Skywatching (1994). In his highlights of Sky Chart 1, “Northern Latitudes Looking South,” Levy exemplifies March and April’s interesting bright star patterns with the Heavenly G.

Levy’s description units seven stars from five constellations. He begins the asterism at red Aldebaran (α Tauri, Alpha Tauri; α Tau, Alpha Tau) in Taurus the Bull constellation. His tracing continues to sextuple star system Castor (α Geminorum, Alpha Geminorum; α Gem, Alpha Gem) and orange-hued Pollux (β Geminorum, Beta Geminorum; β Gem, Beta Gem) in Gemini the Twins constellation. The asterism swings to white-hued binary star Procyon (α Canis Minoris, Alpha Canis Minoris; α CMi, Alpha CMi) in Canis Minor the Lesser Dog constellation and then catches white to blue-white binary star Sirius (α Canis Majoris, Alpha Canis Majoris; α CMa, Alpha CMa) in Canis Major the Greater Dog constellation. The asterism then rounds to blue-white multiple star system Rigel (β Orionis, Beta Orionis; β Ori, Beta Ori) in Orion the Hunter constellation. The starry G takes shape with a brake at Rigel to indent within Orion for the asterism’s final point, red Betelgeuse (α Orionis, Alpha Orionis; α Ori, Alpha Ori).

American physicist David L. Huestis of Skyscrapers Inc. Amateur Astronomical Society of Rhode Island, the United Kingdom-based Society for Popular Astronomy (SPA) and Whitby & District Astronomical Society in North Yorkshire, North East England, shape the Heavenly G with eight stars from six constellations. This version of the asterism begins with golden quadruple star system Capella (α Aurigae, Alpha Aurigae; α Aur, Alpha Aur) in Auriga the Charioteer constellation. This variation agrees with Levy’s next five stars as Gemini’s Castor and Pollux, Canis Major’s Procyon, Canis Major’s Sirius and Orion’s Rigel curve the celestial letter. Rather than braking at Rigel, however, this form of the asterism continues to Taurus the Bull’s Aldebaran, which was the starting point for Levy’s Heavenly G. The indent from Aldebaran back to Orion’s Betelgeuse completes the asterism.

Christine Kronberg’s Table of Asterisms on her USM (Universitäts-Sternwarte München; University Observatory Munich)- and LRZ (Leibniz-Rechenzentrum; Leibniz Supercomputing Centre)-sponsored site, The Munich Astro Archive (MAA), identifies nine stars in six constellations for the G-shaped asterism. Her Heavenly G agrees with Levy’s version by starting with Aldebaran in Taurus. Kronberg agrees with Skyscrapers Inc. and Whitby & District astronomical societies and the Society for Popular Astronomy by including Auriga’s Capella. Kronberg’s asterism then follows the usual trek through Castor and Pollux, Procyon, Sirius and Rigel. Her G, however, injects a new player into the asterism by shooting from Rigel to bluish-white Bellatrix (γ Orionis, Gamma Orionis; γ Ori, Gamma Ori), which sits in the opposite shoulder from Betelgeuse. The indent for Betelgeuse occurs at Bellatrix.

In his Sky & Telescope article for Jan. 13, 2016, American amateur astronomer Robert P. “Bob” King notes that refashioning the Winter Hexagon into the Heavenly G allows Betelgeuse, excluded from the Hexagon’s “geometric merrymaking,” to achieve inclusion “in the Heavenly G, completing the letter’s inner lobe.” King’s variant of the Heavenly G names eight stars in six constellations. King’s Heavenly G agrees with Kronberg’s version for the first seven named stars, Aldebaran through Rigel. King’s G, however, shoots from Rigel to an unnamed star in Orion’s bow before indenting for Betelgeuse.

Bob “Astrobob” King notes that the Winter Hexagon morphs into the Winter Heptagon with the addition of a seventh star, Castor, to the Hexagon’s grouping of Aldebaran, Capella, Pollux, Procyon, Sirius and Rigel. The Winter Hexagon and the Winter Heptagon are also known as the Winter Circle. In their home telescope guide to the night sky, Turn Left at Orion (2011), American research astronomer Guy Consolmagno and geophysicist Daniel M. “Dan” Davis identify the bright encircling of Betelgeuse as a January to March sky guidepost. First magnitude stars Sirius, Rigel, Procyon, Aldebaran and Pollux and second magnitude star Castor “make a ring” around first magnitude star Betelgeuse.

The takeaway for the Heavenly G asterism that indents rather than encircles Betelgeuse are that four versions of the starry letter gather together a range of seven to nine stars in five to six constellations and that the G-shaped asterism refashions the Winter Circle or Winter Hexagon asterisms by including Orion’s red Betelgeuse.

one of at least four known versions of the Heavenly G asterism; all versions include Aldebaran, Betelgeuse, Castor and Pollux, Procyon, Rigel and Sirius: Young Stargazers @YoungStargazers, via Twitter March 2, 2019

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

Betelgeuse in Orion the Hunter constellation holds the place of honor in the Heavenly G asterism as the celestial letter’s final lobe; nebulas of the Orion Molecular Cloud complex surround Constellation Orion with Heavenly G participants’ red Betelgeuse (upper left) and bluish-white Rigel (lower right); Thursday, Aug. 23, 2012: Rogelio Bernal Andreo, CC BY SA 3.0 Unported, via Wikimedia Commons @ https://commons.wikimedia.org/wiki/File:Orion_Head_to_Toe.jpg

one of at least four known versions of the Heavenly G asterism; all versions include Aldebaran, Betelgeuse, Castor and Pollux, Procyon, Rigel and Sirius: Young Stargazers @YoungStargazers, via Twitter March 2, 2019, @ https://twitter.com/YoungStargazers/status/1101903919821803521

For further information:

Consolmagno, Guy; and Dan M. Davis. Turn Left at Orion. Fourth edition. Cambridge UK; New York NY: Cambridge University Press, 2011.

Dawson, Mark. “The Heavenly ‘G.’” Whitby & District Astronomical Society > In-Focus. Jan. 31, 2015.
Available @ http://whitby-astronomers.com/focus/heavenly-g

Huestis, Dave. “Observing the Winter Circle.” Skyscrapers Inc. February 2015.
Available @ http://www.theskyscrapers.org/observing-the-winter-circle

King, Bob. “Asterisms for Winter Nights.” Sky & Telescope > Observing. Jan. 13, 2016.
Available @ https://www.skyandtelescope.com/observing/winter-sky-asterisms011320161301/

King, Bob. Night Sky With the Naked Eye: How to Find Planets, Constellations, Satellites and Other Night Sky Wonders Without a Telescope. Salem MA: Page Street Publishing Co., 2016.

Kronberg, Christine. Heavenly G.” the Munich Archive Astromaps > Constellations > Asterisms > Table of Asterisms.
Available @ http://maps.seds.org/Const/asterism.html

Levy, David H. Skywatching. Revised edition. San Francisco CA: Fog City Press, 2007.

Marriner, Derdriu. “Winter Hexagon Asterism Gathers Six Stars From Six Constellations.” Earth and Space News. Wednesday, Jan. 4, 2017.
Available @ https://earth-and-space-news.blogspot.com/2017/01/winter-hexagon-asterism-gathers-six.html

Marriner, Derdriu. “Winter Triangle Is Asterism Within Winter Hexagon Asterism.” Earth and Space News. Wednesday, Jan. 11, 2017.
Available @ https://earth-and-space-news.blogspot.com/2017/01/winter-triangle-is-asterism-within.html

McClure, Bruce. “See the Winter Circle, or Hexagon.” EarthSky > Favorite Star Patterns. Jan. 12, 2019.
Available @ https://earthsky.org/favorite-star-patterns/winter-circle-highlights-brightest-winter-stars

Young Stargazers ‏@YoungStargazers. “Early March evenings start with the main winter constellations dominating the southern sky. Their brightest stars form an asterism known as the "Heavenly G" (1/3).” Twitter. March 2, 2019.
Available @ https://twitter.com/YoungStargazers/status/1101903919821803521