Sickle Asterism in Leo the Lion Also Suggests Backward Question Mark

Summary: The Sickle asterism in Leo the Lion also suggests a backward question mark, as the six-star asterism frames the lion’s head, mane and shoulders.

Leo the Lion constellation, with distinctive Sickle asterism (also seen as backward question mark), above Jupiter; Sunday, March 28, 2004: Till Credner, CC BY SA 3.0 Unported, via Wikimedia Commons

The Sickle asterism in Leo the Lion also suggests a backward question mark, as the six-star asterism marks the constellatory lion’s head, mane and shoulders.

Astronomy defines an asterism (Ancient Greek: ἀστερισμός, asterismós, “group of stars”) as a recognizable pattern of stars occurring within one or more constellations. The Big Dipper asterism takes shape within Ursa Major the Greater constellation. Four stars in four constellations account for the Great Diamond asterism.

An asterism may also occur within an asterism. The Big Dipper contains the Horse and Rider asterism. The Great Diamond asterism contains a Spring Triangle asterism. The Great Diamond’s Spring Triangle also lies within an alternative, larger Spring Triangle asterism.

The Sickle asterism in Leo the Lion comprises six stars. All six stars lie in the Northern Celestial Hemisphere, the northern half of astronomy’s imaginary celestial sphere. Leo the Lion is considered an equatorial constellation. Leo largely resides in the Northern Celestial Hemisphere. Yet, a small part of the Lion’s southeastern extent stretches across the celestial equator to dangle in the Southern Celestial Hemisphere.

Epsilon Leonis (ε Leonis; Epsilon Leo, ε Leo) begins the asterism, tipping the Sickle's blade. The mid-third magnitude star rates as the fifth brightest star in Leo the Lion constellation. The yellow star’s traditional name, Algenubi, derives from Arabic (رأس الأسد الجنوبي rās al-’asad al-janūbī) for “head of the south lion.”

Mu Leonis (μ Leonis; Mu Leo, μ Leo) sits above Epsilon Leonis as the Sickle asterism’s northernmost star. The fourth magnitude star’s traditional name, Rasalas, derives from Arabic (رأس الأسد الشمالي ra’s al-’asad al-šamālī) for “head of the north lion.”

University of Illinois Professor Emeritus James B. “Jim” Kaler concurs with American amateur astronomer Richard Hinckley Allen’s (Aug. 4, 1838-Jan. 14, 1908) explanation of the Arabic traditional names for the Sickle asterism’s topmost stars. Allen understands the names as referencing Algenubi’s and Rasalas’ positions in the southern and northern parts of Leo’s head, respectively.

Zeta Leonis (Zeta Leonis, ζ Leonis; Zeta Leo, ζ Leo) rests at about the halfway point on the Sickle asterism’s semicircular blade. The barely third magnitude star’s traditional name, Adhafera, derives from Arabic (الضفيرة al-ðafīrah) for “curl of hair.” The traditional visualization of constellation Leo places Adhafera in the protectively thick mane of hair around the Lion’s neck.

Gamma Leonis (γ Leonis; Gamma Leo, γ Leo) lies slightly southwest of Zeta Leonis. The double star comprises a second magnitude, orange primary and a fourth magnitude greenish yellow secondary. Kaler notes that the components’ combined glow yields “a near-perfect mid-second (1.99)” apparent visual magnitude. Gamma Leonis shines as Leo the Lion constellation’s second brightest star and as the brightest star in the blade part of the Sickle asterism. The binary star system’s traditional name, Algieba, may derive from Arabic (الجبهة, Al-Jabhah) for “front, forehead.” Allen suggests an Arabicization of Latin (juba) for mane.

Eta Leonis (η Leonis; Eta Leo, η Leo) represents the meeting point of the Sickle asterism’s blade and handle. The fourth magnitude white star lacks a proper name.

The Sickle asterism’s handle ends with Alpha Leonis (α Leonis; Alpha Leo, α Leo). The first magnitude quadruple star system is composed of two pairs of doubles. Alpha Leonis shines as the brightest star in the Sickle asterism and as the brightest star in Leo the Lion constellation. Alpha Leonis derives its traditional name, Regulus, from Latin (Rēgulus) for "prince, little king."

The Sickle asterism’s distinctive shape aids in easily locating Leo the Lion constellation in night’s skies. Whether interpreted as a sickle or as a backward question mark, the pattern of six stars is readily recognizable.

The takeaways for the Sickle asterism in Leo the Lion constellation are that the asterism’s six stars also suggest a backward question mark, that the constellation’s brightest star appears in the asterism and that, whatever the visualization, the asterism in the Lion’s mane helps locate Leo the Lion in the nighttime sky.

Leo constellation map credit: IAU and Sky & Telescope (Roger Sinnott and Rick Fienberg; constellation patterns by Alan MacRoberts), CC BY 4.0 International, via IAU (International Astronomical Union)

Acknowledgment

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

Image credits:

Leo the Lion constellation, with distinctive Sickle asterism (also seen as backward question mark), above Jupiter; Sunday, March 28, 2004: Till Credner, CC BY SA 3.0 Unported, via Wikimedia Commons @ https://commons.wikimedia.org/wiki/File:LeoCC.jpg

Leo constellation map credit: IAU and Sky & Telescope (Roger Sinnott and Rick Fienberg; constellation patterns by Alan MacRoberts), CC BY 4.0 International, via IAU (International Astronomical Union) @ https://www.iau.org/public/themes/constellations/#com

For further information:

Allen, Richard Hinckley. Star-Names and Their Meanings. New York NY; Leipzig, Germany; London, England; Paris, France: G.E. Stechert, 1899.
Available via Internet Archive @ https://archive.org/details/starnamesandthe00allegoog/

Garfinkle, Robert A. (Allen). Star-Hopping: Your Visa to Viewing the Universe. Cambridge, UK; New York NY; Melbourne, Australia: Cambridge University Press, 1994.

Kaler, James B. (Jim). “Adhafera (Zeta Leonis).” University of Illinois Astronomy Department > Star of the Week.
Available @ http://stars.astro.illinois.edu/sow/adhafera.html

Kaler, James B. (Jim). “Algenubi (Epsilon Leonis).” University of Illinois Astronomy Department > Star of the Week.
Available @ http://stars.astro.illinois.edu/sow/algenubi.html

Kaler, James B. (Jim). “Algieba (Gamma Leonis).” University of Illinois Astronomy Department > Star of the Week.
Available @ http://stars.astro.illinois.edu/sow/algieba.html

Kaler, James B. (Jim). “Leo.” University of Illinois Astronomy Department > Star of the Week.
Available @ http://stars.astro.illinois.edu/sow/leo-t.html

Kaler, James B. (Jim). “Rasalas (Mu Leonis).” University of Illinois Astronomy Department > Star of the Week.
Available @ http://stars.astro.illinois.edu/sow/rasalas.html

Kaler, James B. (Jim). “Regulus (Alpha Leonis).” University of Illinois Astronomy Department > Star of the Week.
Available @ http://stars.astro.illinois.edu/sow/regulus.html

Learn to Skywatch @Learntoskywatch. “Tonight's Target: The Lion's Mane Can you find "The Sickle" in the constellation Leo? Hint: The Big Dipper points the way.” Facebook. March 22, 2017.
Available @ https://www.facebook.com/Learntoskywatch/photos/a.223850584681982/371422216591484/

Marriner, Derdriu. “Alternative Spring Triangle Asterism Replaces Denebola With Regulus.” Earth and Space News. Wednesday, April 10, 2019.
Available @ https://earth-and-space-news.blogspot.com/2019/04/alternative-spring-triangle-asterism.html

Marriner, Derdriu. “Discerning Alcor in Horse and Rider Asterism Tests 20/20 Vision.” Earth and Space News. Wednesday, May 31, 2017.
Available @ https://earth-and-space-news.blogspot.com/2017/05/discerning-alcor-in-horse-and-rider.html

Marriner, Derdriu. “Great Diamond Asterism Gathers Four Stars From Four Constellations.” Earth and Space News. Wednesday, March 27, 2019.
Available @ https://earth-and-space-news.blogspot.com/2019/03/great-diamond-asterism-gathers-four.html

Marriner, Derdriu. “Spring Triangle Asterism Is an Asterism Within Great Diamond Asterism.” Earth and Space News. Wednesday, April 3, 2019.
Available @ https://earth-and-space-news.blogspot.com/2019/04/spring-triangle-asterism-is-asterism.html

McClure, Bruce. “Leo? Here’s Your Constellation.” EarthSky > Constellations. April 15, 2017.
Available @ https://earthsky.org/constellations/leo-heres-your-constellation

Sessions, Larry. "Quietly, Regulus Ushers in Springtime." EarthSky > Brightest Stars. March 6, 2018.
Available @ https://earthsky.org/brightest-stars/best-regulus-the-heart-of-the-lion