| 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 |
0.996 |
| 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 |
-18.5543 |
+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) |
| 2026-05-12 00:00 |
23:57:41.29 |
+54:45:36.2 |
HIP 118287 |
16.52 |
| 2026-05-12 12:00 |
23:57:45.09 |
+54:46:18.9 |
HIP 118287 |
16.19 |
| 2026-05-13 00:00 |
23:57:48.84 |
+54:47:01.7 |
HIP 118287 |
15.92 |
| 2026-05-13 12:00 |
23:57:52.56 |
+54:47:44.6 |
HIP 118287 |
15.70 |
| 2026-05-14 00:00 |
23:57:56.24 |
+54:48:27.6 |
HIP 118287 |
15.53 |
| 2026-05-14 12:00 |
23:57:59.89 |
+54:49:10.8 |
HIP 118287 |
15.42 |
| 2026-05-15 00:00 |
23:58:03.49 |
+54:49:54.2 |
HIP 118287 |
15.36 |
| 2026-05-15 12:00 |
23:58:07.06 |
+54:50:37.7 |
HIP 118287 |
15.37 |
| 2026-05-16 00:00 |
23:58:10.59 |
+54:51:21.3 |
HIP 118287 |
15.43 |
| 2026-05-16 12:00 |
23:58:14.07 |
+54:52:05.0 |
HIP 118287 |
15.54 |
| 2026-05-17 00:00 |
23:58:17.52 |
+54:52:48.8 |
HIP 118287 |
15.71 |
| 2026-05-17 12:00 |
23:58:20.93 |
+54:53:32.8 |
HIP 118287 |
15.94 |
| 2026-05-18 00:00 |
23:58:24.30 |
+54:54:16.9 |
HIP 118280 |
15.84 |
| 2026-05-18 12:00 |
23:58:27.63 |
+54:55:01.1 |
HIP 118280 |
14.96 |
| 2026-05-19 00:00 |
23:58:30.92 |
+54:55:45.4 |
HIP 118280 |
14.09 |
| 2026-05-19 12:00 |
23:58:34.17 |
+54:56:29.8 |
HIP 118280 |
13.22 |
| 2026-05-20 00:00 |
23:58:37.38 |
+54:57:14.4 |
HIP 118280 |
12.35 |
| 2026-05-20 12:00 |
23:58:40.55 |
+54:57:59.0 |
HIP 118280 |
11.48 |
| 2026-05-21 00:00 |
23:58:43.68 |
+54:58:43.7 |
HIP 118280 |
10.61 |
| 2026-05-21 12:00 |
23:58:46.76 |
+54:59:28.5 |
HIP 118280 |
9.75 |
| 2026-05-22 00:00 |
23:58:49.80 |
+55:00:13.4 |
HIP 118280 |
8.90 |
| 2026-05-22 12:00 |
23:58:52.80 |
+55:00:58.4 |
HIP 118280 |
8.04 |
| 2026-05-23 00:00 |
23:58:55.76 |
+55:01:43.5 |
HIP 118280 |
7.20 |
| 2026-05-23 12:00 |
23:58:58.68 |
+55:02:28.7 |
HIP 118280 |
6.36 |
| 2026-05-24 00:00 |
23:59:01.55 |
+55:03:13.9 |
HIP 118280 |
5.53 |
| 2026-05-24 12:00 |
23:59:04.39 |
+55:03:59.3 |
HIP 118280 |
4.72 |
| 2026-05-25 00:00 |
23:59:07.18 |
+55:04:44.7 |
HIP 118280 |
3.93 |
| 2026-05-25 12:00 |
23:59:09.92 |
+55:05:30.1 |
HIP 118280 |
3.18 |
| 2026-05-26 00:00 |
23:59:12.63 |
+55:06:15.7 |
HIP 118280 |
2.51 |
| 2026-05-26 12:00 |
23:59:15.28 |
+55:07:01.3 |
HIP 118280 |
1.98 |
| 2026-05-27 00:00 |
23:59:17.90 |
+55:07:46.9 |
HIP 118280 |
1.74 |
| 2026-05-27 12:00 |
23:59:20.47 |
+55:08:32.7 |
HIP 118280 |
1.89 |
| 2026-05-28 00:00 |
23:59:23.00 |
+55:09:18.4 |
HIP 118280 |
2.36 |
| 2026-05-28 12:00 |
23:59:25.49 |
+55:10:04.3 |
HIP 118280 |
3.01 |
| 2026-05-29 00:00 |
23:59:27.93 |
+55:10:50.2 |
HIP 118280 |
3.73 |
| 2026-05-29 12:00 |
23:59:30.33 |
+55:11:36.1 |
HIP 118280 |
4.49 |
| 2026-05-30 00:00 |
23:59:32.68 |
+55:12:22.1 |
HIP 118280 |
5.28 |
| 2026-05-30 12:00 |
23:59:34.98 |
+55:13:08.1 |
HIP 118280 |
6.08 |
| 2026-05-31 00:00 |
23:59:37.25 |
+55:13:54.2 |
HIP 118280 |
6.89 |
| 2026-05-31 12:00 |
23:59:39.46 |
+55:14:40.3 |
HIP 118280 |
7.70 |
| 2026-06-01 00:00 |
23:59:41.64 |
+55:15:26.4 |
HIP 118280 |
8.52 |
| 2026-06-01 12:00 |
23:59:43.76 |
+55:16:12.6 |
HIP 118280 |
9.34 |
| 2026-06-02 00:00 |
23:59:45.85 |
+55:16:58.8 |
HIP 118280 |
10.15 |