We report spectra from 3000-5900 Å for comet 96P/Machholz , obtained on 2007 Apr 27 UT with the 3-m Shane telescope at Lick Observatory .
The spectra are extremely carbon poor , and show a prominent NH _ { 2 } series , but no CN emission .
NH , NH _ { 2 } , and C _ { 2 } gas production rates are ( 8.36 \pm 2.18 ) \times 10 ^ { 25 } , ( 29.88 \pm 3.66 ) \times 10 ^ { 25 } , and ( 4.52 \pm 0.61 ) \times 10 ^ { 23 } molecules sec ^ { -1 } , respectively , as determined from Haser model fits to the data .
Upper limits to the gas production rates for CN and C _ { 3 } are 7.5 \times 10 ^ { 22 } and 2.0 \times 10 ^ { 23 } , respectively .
Though 96P is depleted in C _ { 2 } and C _ { 3 } relative to NH , it is even more depleted in CN than other so-called “ carbon-chain depleted ” comets .