Stars You Should Know—Summer
(Dave Chapman, 2023)
Coming up:
Fall (September)
South Polar (November)
Focussing on classic Greek-Roman names with occasional indigenous references. The classic names are used in some GoTo telescope software for sky alignment (e.g. Sky-Watcher SynScan and Celestron).
Spectral classes O B A F G K M — Annie Jump Cannon
References:
Star Tales (2018) Ian Ridpath
Star Names (1963) Richard Hinckley Allen
Sky Safari 7 Pro (star lore by Jim Kaler)
A Concise Dictionary of Astronomy (1991) Jacqueline MItton
Stars You Should Know—Summer
9 bright stars —from mag. 0 to mag. 6 (9 OK to find, even in the city)
—8 are used for celestial navigation (58 in all)
—several Sky-Watcher SynScan and Celestron alignment stars
3 dimmer stars of interest
LYRA “The Lyre or Harp”
Vega – alpha Lyrae “Swooping Vulture or Eagle”
– mag. 0 variable multiple star, blue-white A0 main-sequence
– classic navigation star, Sky-watcher and Celestron alignment star
– first star to be photographed, spectrum-analysed, and distance measured by parallax
– home to fictional alien civilization in “Contact”
Epsilon Lyrae “Double Double”
– pair of mag. 4–5 stars each of which is also double
– easily observable in binos (208”)
– each component is also double (5.1, 6.1, 2.1”) and (5.3, 5.4 ,2.4”)
– test of telescope optics and seeing conditions
– white A main-sequence stars
CYGNUS “The Swan”
ASTERISM—NORTHERN CROSS
Deneb – alpha Cygni “Tail” of the Swan
– mag. 1 variable double star
– blue A2 supergiant
– classic navigation star, Sky-watcher and Celestron alignment star
– North America Nebula within a binocular field
Albireo – beta Cygni “Beak” of the Swan
– mag. 3 variable coloured double star, gold/blue pair (3.2, 4.7, 35”)
– orange K3 giant and blue-white B8 main-sequence
– Sky-watcher alignment star
– Visible in binoculars, a crowd-pleaser in telescopes
– Coathanger star cluster close by
61 Cygni “The Flying Star”
– mag. 5 multiple star
– pair of orange K5 & K7 dwarf stars (5.2, 6.0, 32”) easily split in binoculars
– Piazzi (1792) discovered large proper motion
– Bessel (1830) measured distance by parallax
– 15th nearest star (11.4 ly)—possibility of a nearby planet inspired the 1953 sci-fi
story Mission to Gravity by Hal Clement
AQUILA “The Eagle”
Altair – alpha Aquilae “The Flying Eagle”
– mag. 1 multiple star, yellow-white A7 warf
– classic navigation star, Sky-watcher and Celestron alignment star
– Forbidden Planet (1956) was set on fictitious planet Altair IV
ASTERISM—THE SUMMER TRIANGLE (Deneb, Altair, VEga) or DAVE
SCORPIUS “The Scorpion”
Antares – alpha Scorpii “Rival of Mars”
– Cor Scorpionis—the Heart of the Scorpion
– mag. 1 variable double star, red M1.5 supergiant
– flanked by sigma and tau Scorpii, both named Alniyat (The Arteries)
– nice binocular field with globular cluster M4 and very wide open cluster Cr 302
– classic navigation star, Sky-watcher and Celestron alignment star
Shaula – lambda Scorpii “The Stinger”
– mag. 2 variable multiple star, blue-white B1.5 subgiant
– Shaula and nearby Leasath (upsilon Scorpii) make up the stinger
– classic navigation star, Sky-watcher and Celestron alignment star
– Ptolemy’s Cluster (M7) is a fine open cluster one binocular field to the northeast
– most southerly Messier object –35 degrees
SAGITARIUS “The Archer”
ASTERISM—THE TEAPOT
Nunki – sigma Sagitarii
– mag. 2 double star, blue B3 main-sequence
– brightest star in the handle of The Teapot
– classic navigation star, Sky-watcher and Celestron alignment star
– fine globular cluster M22 is a binocular field to the northwest
Kaus Australis – epsilon Sagitarius “Southern tip of the Archer’s Bow”
– Kaus Media (delta Sgr) and Kaus Borealis (lamnda Sgr) complete the bow
– also the base of the Teapot spout
– mag. 3 double star, blue-white A0 giant
– classic navigation star, Sky-watcher and Celestron alignment star
– Ptolemy’s Cluster (M7) is a fine open cluster one binocular field to the west
OPHIUCHUS “The Serpent Bearer”
Rasalhague- alpha Ophiuchi “Head of the Serpent Collector”
– mag. 2 double star, white A5 giant
– classic navigation star, Sky-watcher and Celestron alignment star
– to the south, two binocular fields away, is Taurus Poniatovii (defunct constellation)
– see https://cosmicpursuits.com/3407/going-deep-in-taurus-poniatowski/
– also Actual Astronomy #234 with Brian Ventrudo
Barnard’s Star – V2500 Ophiuchi
– mag. 9 star, orange-red M3.5 dwarf
– highest proper motion (1/4 degree in human lifetime)
– closest star visible from Canada
– within Taurus P.
The Actual Astronomy Podcast 