Globe at Night 2018 Second Perseus and Grus Campaigns Begin Nov. 29

Summary: The Globe at Night 2018 Second Perseus and Grus campaigns begin Thursday, Nov. 29, in the Northern Hemisphere and the Southern Hemisphere, respectively.

Grus the Crane’s first and second brightest stars, Alnair (Alpha Gruis) and Tiaki (Beta Gruis): Gustav Lindqvist @Gurrsnurr, via Twitter March 15, 2015

The Globe at Night 2018 second Perseus and Grus campaigns begin Thursday, Nov. 29, and close Saturday, Dec. 8, as checks of light pollution effects on visibility of Perseus the Hero in the Northern Hemisphere and Grus the Crane constellation in the Southern.

The November-to-December constellation campaigns open as the second of two 2018 Perseus and Grus campaigns. Globe at Night ran the first Perseus and Grus campaigns from Tuesday, Oct. 30, through Thursday, Nov. 8.

Perseus the Hero is considered a Northern Hemisphere constellation. Its placement occurs in the Northern Celestial Hemisphere, the northern half of the imaginary sphere projected by astronomy into space. Perseus resides north of the celestial equator, astronomy’s imaginary projection of Earth’s equator onto the abstract celestial sphere.

Learn to Skywatch suggests finding Perseus by way of the Hero’s northern neighbor Cassiopeia. Gamma Cassiopeiae (γ Cassiopeiae; Gamma Cas, γ Cas) and Delta Cassiopeiae (δ Cassiopeiae; Delta Cas, δ Cas), the two stars in the Seated Queen’s less-defined vee, point to Eta Persei (η Persei; Eta Per, η Per) at the tip of the Hero’s fishhook. The eight-star fishhook also includes Gamma Persei (γ Persei; Gamma Per, γ Per), Mirfak (Alpha Persei, α Persei; Alpha Per, α Per), Delta Persei (δ Persei; Delta Per, δ Per), Mu Persei (Mu Per, μ Persei, μ Per), 48 Persei (c Persei, 48 Per, HR 1273, HIP 19343, or HD 25940), b Persei (HD 26961) and, at the fish hook’s tail, Lambda Persei (λ Persei; Lambda Per, λ Per).

The Hero’s fishhook overlaps with the constellation’s other finding aid, a wishbone. The six-star wishbone shares Gamma Persei, Mirfak (Alpha Persei) and Delta Persei with the fishhook. Epsilon Persei (ε Persei; Epsilon Per, ε Per), Beta Persei (β Persei; Beta Per, β Per) and Zeta Persei (ζ Persei; Zeta Per, ζ Per) form the wishbone’s fork.

Globe at Night provides eight magnitude charts for each campaign. Magnitude zero represents a cloudy sky. Magnitude seven presents a star-filled sky. Beta Persei, known traditionally as Algol, is visible at all targeted latitudes, 0 to 50 degrees north, according to Globe at Night’s charts for magnitudes two through seven.

Globe at Night’s simultaneous Southern Hemisphere campaign focuses on Grus the Crane constellation. Location in the Southern Celestial Hemisphere qualifies Grus as a Southern Hemisphere constellation. Constellation Guide website indicates Grus the Crane’s visibility as extending beyond the Southern Hemisphere. The Crane offers visibility in the Northern Hemisphere to observers at equatorial latitudes up to 34 degrees north latitude.

The Crane’s constellatory neighbors are all Southern Celestial Hemisphere residents. Sculptor and Piscis Austrinus the Southern Fish lie to the north. Tucana the Toucan and Indus the Indian are adjacent to the Crane’s southern boundary. Eastern and western neighbors are Phoenix the Phoenix and Microscopium the Microscope, respectively.

Grus the Crane’s placement near other constellations’ brightest stars facilitates identification. Eridanus the River’s brightest star, Achernar (Alpha Eridani, α Eridani; Alf Eri, α Eri), and Piscis Austrinus the Southern Fish’s brightest star, Fomalhaut (Alpha Piscis Austrini, α Piscis Austrini; Alpha PsA, α PsA), frame the Crane.

Globe at Night’s website notes the triangle formed by the Crane’s three brightest stars. Alpha Gruis (α Gruis; Alpha Gru, α Gru) perches at the triangle’s apex. Known traditionally as Alnair (Arabic: al-nayyir, “the bright one”), Alpha Gruis is the Crane’s brightest star. The Crane’s second and third brightest stars, Beta Gruis (β Gruis; Bet Gru, β Gru) and Gamma Gruis (γ Gruis; Gam Gru, γ Gru), respectively, anchor the triangle’s sides.

Alnair and Beta Gruis are visible on Globe at Night’s charts for targeted latitudes 10 to 40 degrees south at magnitudes two through seven. They are not visible at the two lowest magnitudes, zero and one.

The takeaways for the Globe at Night 2018 second Perseus and Grus campaigns, which simultaneously run from Thursday, Nov. 29, through Saturday, Dec. 8, are that both campaigns close as the second of two 2018 Hero and Crane campaigns and that their completion signals the end of Globe at Night’s 2018 campaigns in the Northern Hemisphere and the Southern Hemisphere.

Perseus the Hero constellation lies between distinctively shaped Cassiopeia the Seated Queen constellation and Auriga the Charioteer constellation’s brightest star, Capella: Learn to Skywatch @Learntoskywatch, via Twitter Nov. 27, 2017

Acknowledgment

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

Image credits:

Grus the Crane’s first and second brightest stars, Alnair (Alpha Gruis) and Tiaki (Beta Gruis): Gustav Lindqvist @Gurrsnurr, via Twitter March 15, 2015, @ https://twitter.com/Gurrsnurr/status/577085245876502528

Perseus the Hero constellation lies between distinctively shaped Cassiopeia the Seated Queen constellation and Auriga the Charioteer constellation’s brightest star, Capella: Learn to Skywatch @Learntoskywatch, via Twitter Nov. 27, 2017, @ https://twitter.com/Learntoskywatch/status/935221889034747904

For further information:

“Can You Find Grus?” Globe at Night > Finding Constellations.
Available @ https://www.globeatnight.org/finding/grus

“Can You Find Perseus?” Globe at Night > Finding Constellations.
Available @ https://www.globeatnight.org/finding/perseus

Gustav Lindqvist ‏@Gurrsnurr. “Ute och kollar stjärnor @Zelolule Grus can be found south of the constellation of Piscis Austrinus, the southern fish.” Twitter. March 15, 2015.
Available @ https://twitter.com/Gurrsnurr/status/577085245876502528

Learn to Skywatch @Learntoskywatch. “Tonight's Target: The Constellation Perseus.” Twitter. Nov. 27, 2017.
Available @ https://twitter.com/Learntoskywatch/status/935221889034747904

Marriner, Derdriu. “Globe at Night 2018 Bootes and Crux Campaigns Happen in May.” Earth and Space News. Wednesday, May 9, 2018.
Available @ https://earth-and-space-news.blogspot.com/2018/05/globe-at-night-2018-bootes-and-crux.html

Marriner, Derdriu. “Globe at Night 2018 Cygnus and Second Scorpius Campaigns Begin Aug. 2.” Earth and Space News. Wednesday, Aug. 1, 2018.
Available @ https://earth-and-space-news.blogspot.com/2018/08/globe-at-night-2018-cygnus-and-second.html

Marriner, Derdriu. “Globe at Night 2018 Hercules and Third Crux Campaigns Begin June 4.” Earth and Space News. Wednesday, May 30, 2018.
Available @ https://earth-and-space-news.blogspot.com/2018/05/globe-at-night-2018-hercules-and-third.html

Marriner, Derdriu. “Globe at Night 2018 Leo Campaign Begins April 6 for Northern Latitudes.” Earth and Space News. Wednesday, April 4, 2018.
Available @ https://earth-and-space-news.blogspot.com/2018/04/globe-at-night-2018-leo-campaign-begins.html

Marriner, Derdriu. “Globe at Night 2018 Pegasus and Second Sagittarius Campaigns Begin Oct. 1.” Earth and Space News. Wednesday, Sept. 26, 2018.
Available @ https://earth-and-space-news.blogspot.com/2018/09/globe-at-night-2018-pegasus-and-second.html

Marriner, Derdriu. “Globe at Night 2018 Perseus and Grus Campaigns Begin Oct. 30.” Earth and Space News. Wednesday, Oct. 24, 2018.
Available @ https://earth-and-space-news.blogspot.com/2018/10/globe-at-night-2018-perseus-and-grus.html

Marriner, Derdriu. “Globe at Night 2018 Sagittarius and Second Cygnus Campaigns Begin Sept. 1.” Earth and Space News. Wednesday, Aug. 22, 2018.
Available @ https://earth-and-space-news.blogspot.com/2018/08/globe-at-night-2018-sagittarius-and.html

Marriner, Derdriu. “Globe at Night 2018 Scorpius and Second Hercules Campaigns Begin July 4.” Earth and Space News. Wednesday, June 27, 2018.
Available @ https://earth-and-space-news.blogspot.com/2018/06/globe-at-night-2018-scorpius-and-second.html