The selection rules for vibration rotation transitions are J’= 5 The selection rules for vibration rotation transitions are ∆v = ±1 ∆J = ±1 v” J”= 5

Excited Electronic State J’= 5 v’ = 0 R(3) R(2) R(1) R(0) v” = 0 J”= 5 R Branch

Excited Electronic State J’= 5 v’ = 0 P(4) R(3) P(3) R(2) P(2) R(1) P(1) R(0) v” = 0 J”= 5 R Branch P Branch

Excited Electronic State J’= 5 v’ = 0 P(4) R(3) P(3) R(2) P(2) R(1) P(1) R(0) v” = 0 J”= 5 R Branch P Branch

Excited Electronic State J’= 5 v’ = 0 P(4) R(3) P(3) R(2) P(2) R(1) P(1) R(0) v” = 0 J”= 5 Central section of the CN 0-0 Band R Branch P Branch

Rotational Structure of the 0-0 band of CN at 3883Å observed from Comet Bennett (1970 II)

NASA Comet image Harry Kroto 2004

Rotational Structure of the 0-0 band of CN at 3883Å observed from Comet Bennett (1970 II) Harry Kroto 2004

Harry Kroto 2004

Rotational Structure of the 0-0 band of CN at 3883Å observed from Comet Bennett (1970 II) Harry Kroto 2004

Electronic Emission Spectrum 3883 Å 4216 Å 4606 Å CN Violet Electronic Emission Spectrum 0-1 0-2 0-0 R(0) P(1) R Branch P Branch 25850 25750 cm-1 25750 cm-1 Rotational Structure of the 0-0 band of CN at 3883Å observed from Comet Bennett (1970 II)

J V’ J V”

J + 1 J V’ J – 1 J V”

J + 1 J B’ J (J+ 1) V’ J – 1 J B”J (J+ 1) V”

J + 1 B’ (J+ 1)(J+2) J B’ J (J+ 1) V’ J – 1 J B”J (J+ 1) V”

J + 1 B’ (J+ 1)(J+2) J B’ J (J+ 1) V’ J – 1 B’ (J – 1) J J B”J (J+ 1) V”

J + 1 B’ (J+ 1)(J+2) J B’ J (J+ 1) V’ J – 1 B’ (J – 1) J J B”J (J+ 1) V”

J + 1 B’ (J+ 1)(J+2) J B’ J (J+ 1) V’ J – 1 B’ (J – 1) J R(J) J B”J (J+ 1) V”

J + 1 B’ (J+ 1)(J+2) J B’ J (J+ 1) V’ J – 1 B’ (J – 1) J R(J) P(J) J B”J (J+ 1) V”

J + 1 B’ (J+ 1)(J+2) J J – 1 B’ (J – 1) J R(J) P(J) J B”J (J+ 1)

J + 1 B’ (J+ 1)(J+2) B’ (J2 + 3J +2) J J – 1 B’ (J – 1) J R(J) P(J) J B”J (J+ 1) V”

J + 1 B’ (J+ 1)(J+2) B’ (J2 + 3J +2) J J – 1 B’ (J – 1) J B’ (J2 – J) R(J) P(J) J B”J (J+ 1) V”

J + 1 B’ (J+ 1)(J+2) B’ (J2 + 3J +2) J J – 1 B’ (J – 1) J B’ (J2 – J) R(J) P(J) J B”J (J+ 1) V” Harry Kroto 2004

J + 1 B’ (J+ 1)(J+2) B’ (J2 + 3J +2) J J – 1 B’ (J – 1) J B’ (J2 – J) B’ (4J + 2) R(J) P(J) J B”J (J+ 1) V”

J + 1 B’ (J+ 1)(J+2) B’ (J2 + 3J +2) J J – 1 B’ (J – 1) J B’ (J2 – J) B’ (4J + 2) = 4B’(J + ½) R(J) P(J) J B”J (J+ 1) V”

Rotational Structure J’= 5 v’ = 0 v” = 0 J”= 5 R Branch P Branch P(4) P(4) R(3) P(3) R(2) P(2) R(1) P(1) R(0) v” = 0 J”= 5 R Branch P Branch Harry Kroto 2004

Rotational Structure J’= 5 v’ = 0 v” = 0 J”= 5 Central section of the P(4) R(3) P(3) R(2) P(2) R(1) P(1) R(0) v” = 0 J”= 5 Central section of the CN 0-0 Band R Branch P Branch Harry Kroto 2004

Rotational Structure J’= 5 v’ = 0 v” = 0 J”= 5 Central section of the P(4) R(3) P(3) R(2) P(2) R(1) P(1) R(0) v” = 0 J”= 5 Central section of the CN 0-0 Band R Branch P Branch Harry Kroto 2004

Rotational Structure J’= 5 v’ = 0 v” = 0 J”= 5 R Branch P Branch P(4) P(4) R(3) P(3) R(2) P(2) R(1) P(1) R(0) v” = 0 J”= 5 R Branch P Branch Harry Kroto 2004

Harry Kroto 2004

Harry Kroto 2004

Harry Kroto 2004

Harry Kroto 2004

Electronic Emission Spectrum of CN Radical in a Bunsen Burner Flame v’= 0 C + N v”=3 2 1 r  Harry Kroto 2004

Rotational Structure J’= 5 v’ = 0 v” = 0 J”= 5 R Branch P Branch v” = 0 J”= 5 R Branch P Branch Harry Kroto 2004

J’+ 1 B’ (J+ 1)(J+2) R(J) P(1) B” J (J+ 1) J” R Branch If B” ~ B’ o + 2B J Harry Kroto 2004

Harry Kroto 2004

Harry Kroto 2004

Halley Harry Kroto 2004

Halley Harry Kroto 2004

Hale-Bopp Stromboli Observatory Harry Kroto 2004

Harry Kroto 2004

Harry Kroto 2004

Align the spectrometer slit across the split tail Charged species tail Align the spectrometer slit across the split tail Dust and neutral species tail Harry Kroto 2004

Align the spectrometer slit across the split tail Harry Kroto 2004

Align the spectrometer slit across the split tail Charged species tail Align the spectrometer slit across the split tail Harry Kroto 2004

Align the spectrometer slit across the split tail Charged species tail Align the spectrometer slit across the split tail Dust and neutral species tail Harry Kroto 2004

Dust and neutral species tail H2O+ NH2 Charged species tail Dust and neutral species tail Align the spectrometer slit across the split tail Harry Kroto 2004

Two serendipitous radio discoveries Harry Kroto 2004

The Crab Nebula Norwegian Observatory Harry Kroto 2004

Harry Kroto 2004

Harry Kroto 2004

Orion Constellation Harry Kroto 2004