In astronomy ionization of atoms are noted different then in chemistry
Neutral Hydrogen : H I
Neutral Helium : He I
Neutral Calcium : Ca I
Ionized Calcium : Ca II or Ca+ (noted in chemistry)
Clarification of spectral lines of Hydrogen (H I)
For neutral Hydrogen or H I :
Lyman series : transition to groundlevel
Balmer series : transition to energy level 2; all transitions are within visible wavelenght
Paschen series : transition to energy level 3
Brackett series : transition to energy level 4
Pfund series : transition to energy level 5
Humphreys series : transition to energy level 6
Hansen-Strong series : transition to energy level 7
587,5545nm 1s3d 3D1 – 1s2p 3P2
Calcium electron configuration : 1s2 2s2 2p6 3s2 3p6 4s1
Lyman series : transition to groundlevel
Balmer series : transition to energy level 2; all transitions are within visible wavelenght
Paschen series : transition to energy level 3
Brackett series : transition to energy level 4
Pfund series : transition to energy level 5
Humphreys series : transition to energy level 6
Hansen-Strong series : transition to energy level 7
The H-alpha line is due to an electron making a transition between energy level 3 to energy level 2.
Clarification of Helium I (D3) lines
He I (D3) line - 587,572nm via Ortho Helium 1s3d to 1s2p but more in detail :
587,5561nm 1s3d 3D2 – 1s2p 3P2
587,5562nm 1s3d 3D3 – 1s2p 3P2
587,5571nm 1s3d 3D1 – 1s2p 3P1
587,5588nm 1s3d 3D2 – 1s2p 3P1
587,5913nm 1s3d 3D1 – 1s2p 3P0
Clarification of Ca II H and K line
Ca II H line : 396.847nm
Ca II K line : 393.366nm