C/2012 T5 Bressi
more info
Comet C/2012 T5 was discovered on 14 October 2012 by Terry H. Bressi (Spacewatch), that is more than 4 months before its perihelion passage. It was observed until 21 March 2013 (see picture).
C/2012 T5 had its closest approach to the Earth on 25 February 2013 (0.913 au), a day after its perihelion passage.
Comet was lost a month after perihelion passage and Sekanina (2019) concluded that this Oort Cloud comet did not survive the observed perihelion passage.
Original value of 1/a is significantly negative for solutions based on entire data set. The preferred solution (based on pre-perihelion data taken at larger heliocentric distances than 1.33au) gives also negative value of original 1/a; however, within its uncertainty of about 1.5 sigma this comet can came from the Oort Cloud.
See also Królikowska 2020.

solution description
number of observations 702
data interval 2012 10 14 – 2013 03 21
data type significantly more measurements before perihelion (PRE+)
data arc selection entire data set (STD)
range of heliocentric distances 2.58 au – 0.32 au (perihelion) – 0.75 au
type of model of motion NT - non-gravitational orbits for asymmetric, standard g(r)
data weighting YES
number of residuals 1398
RMS [arcseconds] 0.72
orbit quality class 2a
orbital elements (barycentric ecliptic J2000)
Epoch 1717 12 06
perihelion date 2013 02 23.06900328 ± 0.00034405
perihelion distance [au] 0.31309582 ± 0.00000473
eccentricity 1.00004954 ± 0.00000742
argument of perihelion [°] 318.564233 ± 0.000954
ascending node [°] 230.639794 ± 0.000386
inclination [°] 72.035738 ± 0.001329
reciprocal semi-major axis [10-6 au-1] -158.21 ± 23.70
file containing 5001 VCs swarm
2012t5n6.bmi
Time distribution of positional observations with corresponding heliocentric (red curve) and geocentric (green curve) distance at which they were taken. The horizontal dotted line shows the perihelion distance for a given comet whereas vertical dotted line — the moment of perihelion passage.
Six 2D-projections of the 6D space of original swarm including 5001 VCs. Each density map is given in logarithmic scale presented on the right in the individual panel.