  HCN J=1-0 emission from the long-period comet C/2013 R1 (Lovejoy) was
observed from the Onsala Space Observatory on multiple occasions during the
month before its perihelion passage on December 22, 2013. We report detections
for seven different dates, spanning heliocentric distances (R_h) decreasing
from 0.94 to 0.82 au. Estimated HCN production rates are generally higher than
previously reported for the same time period, but the implied increase in
production rate with heliocentric distance, Q_{HCN} proportionate to
R_h^{-3.2}, represent well the overall documented increase since it was first
observed at R_h=1.35. The implied mean HCN abundance relative to water in R1
Lovejoy is 0.2%. We also report on a detection of HCN with the new 3 mm
receiver system at Onsala Space Observatory in comet C/2014 Q2 (Lovejoy) on
January 14, 2015, when its heliocentric distance was 1.3 au. Relative to comet
C/2013 R1 (Lovejoy), the HCN production rate of C/2014 Q2 (Lovejoy) was more
than 5 times higher at similar heliocentric distances, and the implied HCN
abundance relative to water 0.09%.
