| Parameter |
Value |
| Designation |
C/2012 T5 (Bressi) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2013-02-24T01:24:11.816640Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:32:24Z |
| Obs used |
661 |
| NEO |
- |
| M1 |
15.300 |
| K1 |
4.750 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2012-11-22.0000000 |
| e |
1.00043352 |
| q (au) |
0.322826 |
| a (au) |
-744.660040 |
| i (deg) |
72.098415 |
| Ω (om, deg) |
230.594454 |
| ω (w, deg) |
318.094191 |
| M (ma, deg) |
-0.004562 |
Magnitude
Scatter + Global Linear
$$
M_a = (14.819 + 4.103\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
14.819 |
| n |
4.103 |
| gf |
0.997 |
| gb |
-0.787 |
| k |
0.971 |
| δ90 |
9.997 |
| Parameter |
Symbol |
Range |
Description |
| Absolute magnitude at 1 AU from Sun and Earth |
H0 |
-5 to 20 |
Intrinsic brightness of the comet |
| Photometric slope parameter |
n |
2 to 6 |
Rate of brightness change with heliocentric distance |
| Forward scattering asymmetry factor |
gf |
0.8 to 1 |
Degree of forward scattering |
| Backward scattering asymmetry factor |
gb |
-1 to -0.5 |
Degree of backward scattering |
| Partitioning coefficient |
k |
0.8 to 1 |
Ratio between forward/backward scattering contributions |
| Dust-to-gas brightness ratio |
δ90 |
1 to 10 |
Relative contribution of dust scattering to gas emission |
Reference: EPSC-DPS2025-160
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 2012-10-14 |
2012-11-06 |
-18.5544 |
+6.497 |
| 2012-11-06 |
2013-01-07 |
+0.1230 |
+0.205 |
| 2013-01-07 |
2013-02-10 |
+7.5691 |
-0.903 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-07-29 00:00 |
23:58:20.36 |
+56:34:57.0 |
HIP 118172 |
6.70 |
| 2026-07-29 12:00 |
23:58:16.80 |
+56:35:26.1 |
HIP 118172 |
7.17 |
| 2026-07-30 00:00 |
23:58:13.19 |
+56:35:54.9 |
HIP 118172 |
7.67 |
| 2026-07-30 12:00 |
23:58:09.54 |
+56:36:23.4 |
HIP 118172 |
8.19 |
| 2026-07-31 00:00 |
23:58:05.85 |
+56:36:51.6 |
HIP 118172 |
8.73 |
| 2026-07-31 12:00 |
23:58:02.11 |
+56:37:19.4 |
HIP 118172 |
9.28 |
| 2026-08-01 00:00 |
23:57:58.33 |
+56:37:46.9 |
HIP 118172 |
9.85 |
| 2026-08-01 12:00 |
23:57:54.51 |
+56:38:14.1 |
HIP 118172 |
10.43 |
| 2026-08-02 00:00 |
23:57:50.65 |
+56:38:41.0 |
HIP 118172 |
11.02 |
| 2026-08-02 12:00 |
23:57:46.74 |
+56:39:07.5 |
HIP 118172 |
11.62 |
| 2026-08-03 00:00 |
23:57:42.79 |
+56:39:33.7 |
HIP 118172 |
12.23 |
| 2026-08-03 12:00 |
23:57:38.80 |
+56:39:59.6 |
HIP 118172 |
12.84 |
| 2026-08-04 00:00 |
23:57:34.77 |
+56:40:25.1 |
HIP 118172 |
13.46 |
| 2026-08-04 12:00 |
23:57:30.70 |
+56:40:50.3 |
HIP 118172 |
14.08 |
| 2026-08-05 00:00 |
23:57:26.58 |
+56:41:15.1 |
HIP 118059 |
14.42 |
| 2026-08-05 12:00 |
23:57:22.43 |
+56:41:39.6 |
HIP 118059 |
13.88 |
| 2026-08-06 00:00 |
23:57:18.23 |
+56:42:03.8 |
HIP 118059 |
13.37 |
| 2026-08-06 12:00 |
23:57:13.99 |
+56:42:27.5 |
HIP 118059 |
12.87 |
| 2026-08-07 00:00 |
23:57:09.71 |
+56:42:51.0 |
HIP 118059 |
12.40 |
| 2026-08-07 12:00 |
23:57:05.40 |
+56:43:14.1 |
HIP 118059 |
11.96 |
| 2026-08-08 00:00 |
23:57:01.04 |
+56:43:36.8 |
HIP 118059 |
11.54 |
| 2026-08-08 12:00 |
23:56:56.65 |
+56:43:59.2 |
HIP 118059 |
11.17 |
| 2026-08-09 00:00 |
23:56:52.21 |
+56:44:21.2 |
HIP 118059 |
10.83 |
| 2026-08-09 12:00 |
23:56:47.74 |
+56:44:42.8 |
HIP 118059 |
10.54 |
| 2026-08-10 00:00 |
23:56:43.23 |
+56:45:04.1 |
HIP 118059 |
10.30 |
| 2026-08-10 12:00 |
23:56:38.68 |
+56:45:25.0 |
HIP 118059 |
10.11 |
| 2026-08-11 00:00 |
23:56:34.09 |
+56:45:45.5 |
HIP 118059 |
9.97 |
| 2026-08-11 12:00 |
23:56:29.47 |
+56:46:05.6 |
HIP 118059 |
9.89 |
| 2026-08-12 00:00 |
23:56:24.80 |
+56:46:25.4 |
HIP 118059 |
9.87 |
| 2026-08-12 12:00 |
23:56:20.11 |
+56:46:44.8 |
HIP 118059 |
9.91 |
| 2026-08-13 00:00 |
23:56:15.37 |
+56:47:03.8 |
HIP 118059 |
10.01 |
| 2026-08-13 12:00 |
23:56:10.60 |
+56:47:22.4 |
HIP 118059 |
10.17 |
| 2026-08-14 00:00 |
23:56:05.80 |
+56:47:40.7 |
HIP 118059 |
10.38 |
| 2026-08-14 12:00 |
23:56:00.96 |
+56:47:58.5 |
HIP 118059 |
10.64 |
| 2026-08-15 00:00 |
23:55:56.09 |
+56:48:16.0 |
HIP 118059 |
10.96 |
| 2026-08-15 12:00 |
23:55:51.18 |
+56:48:33.1 |
HIP 118059 |
11.32 |
| 2026-08-16 00:00 |
23:55:46.24 |
+56:48:49.7 |
HIP 118059 |
11.72 |
| 2026-08-16 12:00 |
23:55:41.26 |
+56:49:06.0 |
HIP 118059 |
12.16 |
| 2026-08-17 00:00 |
23:55:36.25 |
+56:49:21.9 |
HIP 118059 |
12.64 |
| 2026-08-17 12:00 |
23:55:31.21 |
+56:49:37.4 |
HIP 118059 |
13.14 |
| 2026-08-18 00:00 |
23:55:26.14 |
+56:49:52.5 |
HIP 118059 |
13.67 |
| 2026-08-18 12:00 |
23:55:21.04 |
+56:50:07.2 |
HIP 118059 |
14.23 |
| 2026-08-19 00:00 |
23:55:15.90 |
+56:50:21.5 |
HIP 117810 |
13.64 |