Spectral Lines of Hydrogen, Calcium II H&K and Helium I (D3)

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)

 

Spectral lines can be explained due to electron transitions between energy levels.

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

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 :

587,5545nm 1s3d 3D1 – 1s2p 3P2

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

Calcium electron configuration : 1s2 2s2 2p6 3s2 3p6 4s1

Ca II H line :  396.847nm

Ca II K line :  393.366nm