Jules Janssen
Izgled
(Preusmjereno sa stranice Pierre Janssen)
Pierre Jules César Janssen (22. februar 1824 – 23. decembar 1907), u Francuskoj najčešće navođen kao Jules Janssen, bio je francuski astronom kome se, zajedno sa engleskim naučnikom Josephom Normanom Lockyerom, pripisuje otkriće helija.
Janssen se također bavio fotografijom, te je godine 1895. sudjelovao na kongresu fotografa u Lyonu, čije su sudionike braća Lumiere snimili u jednom od svojih prvih filmova.
- Royal Astronomical Society (1908). Monthly Notices of the Royal Astronomical Society. Priestley and Weale., from Monthly Notices of the Royal Astronomical Society, 1908, vol. 68, pp. 245–249
- Obituary, from Popular Astronomy, 1908, vol. 16, pp. 72–74
- Obituary, from Astronomische Nachrichten, 1908, vol. 177, p. 63 (in French)
- Obituary, from The Astrophysical Journal, 1908, vol. 28, pp. 89–99 (in French)
- 1911 Encyclopædia Britannica Eleventh Edition, entry for Janssen
- Janssen statue, description and black-and-white picture from The Observatory, 1922, vol. 45, pp. 175–176
- Brief biography, from the High Altitude Observatory at Boulder, Colorado
- Janssen's chronophotography