The NEO 2004 TU12 was discovered on 2004 Oct. the 10th by the Siding Spring Survey (Australia) and announced on MPEC 2004-T55, it was classified as an amor object. The night of 2004 Nov the 12th I was at La Cañada, planning observation while waiting for interesting objects to raise, I saw this bright NEO about to cross the meridian in the planetary program, to check that all the systems were working I started a series of images on it. In the very first images of 30 seconds I noticed a faint trace to the north-est originating at the neo and thought that it could be a comet. Stacking many images the trace was clearly visible as a straight tail and in the subframes it was moving as a whole with the nucleus.

It was 2.5 days past perihelion and crossing the ecliptic (near one node)

The CBAT (central bureau for astronomical telegrams) published the IAUC 8436 on 2004 Nov 12th, with the report of the tail detection, a=3 e=0.6 i = 27.8, q= 1.22 Tisserand(j)=2.85 , the new object designation is P/2004 TU12, on 2004 Nov the 24th it was numbered as 162P IAUC 8445.

Circular No. 8436 Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION COMET P/2004 TU_12 (SIDING SPRING) An apparently asteroidal object discovered on Oct. 10 by the Siding Spring Survey (announced as 2004 TU_12 on MPEC 2004-T55; discovery observation below) has been found to show a short eastward tail. CCD images taken over 2.5 hr with the 0.36-m "SoTIE" reflector at Las Campanas by F. Mallia, G. Masi, and R. Wilcox on Nov. 12.0 UT show a tail about 2' long in p.a. 70 deg (the "head" appearing like stars in the field (FWHM about 3"). Eighty 30-s CCD images taken on Nov. 12.8 by J. Lacruz (La Canada, Spain) show a sharp tail 4' long in p.a. 69 deg (and total mag 14.3).

The observations on Nov.12.o UT reported in the IAUC, sent by Masi et al. were published with the asteroidal designation thus no remarks on the cometary appearance were reported yet as in the 2004-Nov-12 Daily Orbit Update :

K04T12U 2C2004 11 12.04523 22 51 33.56 -10 00 17.0 14.2 R EV056I05

K04T12U 2C2004 11 12.04620 22 51 33.58 -10 00 12.1 14.1 R EV056I05

K04T12U 2C2004 11 12.05008 22 51 33.78 -09 59 53.5 14.1 R EV056I05

K04T12U 2C2004 11 12.05494 22 51 34.02 -09 59 29.8 14.1 R EV056I05

However, the observations by J. Lacruz on Nov. 12.8 reported in the same IAUC circular, where published under the new cometary designation some three days later in MPEC 2004-V75 : COMET P/2004 TU12 (SIDING SPRING)

PK04T12U C2004 11 12.76709 22 52 14.38 -09 02 23.2 14.3 T EV075J87

PK04T12U C2004 11 12.76947 22 52 14.49 -09 02 12.1 14.3 T EV075J87

PK04T12U C2004 11 12.77228 22 52 14.64 -09 01 58.5 14.3 T EV075J87

I inspected the images blinking them visually to discover and measure the tail and reported them both to the MPC and CBAT noting the cometary nature of the NEO,

The IAUC does not mention the discoverer.