Algenib II was the second planet in the Algenib, or Alpha Persei system.

It was first charted by Earth Starfleet starship Columbia in 2159, at which time it was observed to be a lifeless world similar to Mercury. In the late 2260s, the USS Enterprise approached within 20 light-years of Algenib II, at which time it appeared to be Class M. Enterprise Captain James T. Kirk assigned Lieutenant Thorvald Pearson, head of stellar cartography, to take a shuttle to the planet to investigate. The shuttle crashed mysteriously, forcing Kirk, along with Spock and McCoy, to beam down and retrieve the missing crewmembers. (TOS short story: "Make-Believe")

The USS Enterprise-E completed a mission to Algenib II in mid-2372. (TNG eBook: The Insolence of Office)

planets visited by the USS Enterprise (NCC-1701) during Captain Kirk's initial five-year mission (2265-2270)
various	Capory
2265	Earth • Draxis II • Tally • Alpha Ortelina VII • Arronus VII • Aldebaran III • M-155 • Mestiko • Tally • Dimorus • Tendar • Archernar IV • Delta Vega I • Miri's homeworld • Starbase 12 • 7348-II • robot planet • Timshel • K-G • Zarta • Metamorpha • Numero Uno • FP-1 • FP-2 • Voodoo planet • Gamma Alpha V • Starbase 8 planet • Pollux II • Dukar • Neesan • Algenib II
2266	Beta IV • Rigel XII • Psi 2000 • Tlaoli IV • Alpha Proxima II • Angira • Exo III • 1324-IV • Canara • Nador • M-113 • Alfa 177 • Planet Q • Benecia • Starbase 11 planet • Theta VII (Rell's world) • Talos IV • Numero Uno • Gateway
2267	Makus III • Beta VI • Janus VI • Omicron Ceti III • Deneva • Ceti Alpha V • Eminiar VII • Babel • Gamma Canaris 527 • Taurus II • Hydra Epsilon III • Ximega II • Perseus Arm planetoid • Starbase 11 planet • Salvum • Grotus • Rifas-L • Amusement Park planet • Heitius VII • Centaurus V • Tyrtaeus II • Gothos • Cestus III • Iron-silica planet • Zutotanium planetoid • Mudd • Earth • Canara • Beta III • Pyris VII • Vulcan • Pollux IV • Argelius II • Halka • Bavarya • Neolithia • Mythra • Capella IV • Magna Roma • Gamma Trianguli VI • Sigma Iotia II • Masaba • Lekythos • Shroud IV • Tycho IV • Donico II • Rimillia • Organia
2268	Narnel's World • Neural • Fornax II • Gamma II • Triskelion • Argus X • Tycho IV • Theta VII • Signi Beta • Earth • Direidi • Eeiauo • Patria I • Leora IV • Academy • Delta Canaris IV • Alnath II • Ammdon • Marcos XII • Amerind • Beta XII-A • Elas • Troyius • Sigma Draconis VI • Ekos • Scalos
2269	Anomaly • Excalbia • Andros • Pollux V • Avalon • Camus II • Tanis • Aleph Prime • Kyros • Viden • Theta Tau V • Aleph III • Trefolg • Mantilles • Merak II • Ardana • Babel • Organia • Gateway
2270	Isitra Zero • Gateway • Mercan • Denebia • Phylos II • Amusement Park planet • Motherlode • Megas-Tu • Terratin • Sherman's Planet • Argo • Vedala asteroid • Dramia II • Arret • Lactra VII • Delta Theta III • Archernar IV • Cenotaph • Taygeta V • Okeanos • Yoondri • Aleriad • Mercan • Aritani • Yalbo • Sycorax • Talos IV • Earth • Starbase 12 • Tomarii

planets visited by the USS Enterprise (NCC-1701-E)

Earth • Elamin IX • Algenib II • Salva IV • Chiaros IV • Kendaray • Denobula • Galor IV • Gornar • Betazed • Raknal V • Ba'ku • Halka • Primus IV • Gemworld • TaD • Blossom IV • Terra Galan • Bajor • Narendra III • Pelleus V • Solosos III • Davlos VI • Cygnet IV • Myrmidon • Tezwa • Kolarus III • Romulus • Tolochon II • Dokalaan homeworld • Dokaalan colony • Carrea • Delta Sigma IV • Gorsach IX • Trophy World • Ramatis III • Fromander IV • Vulcan