| Parameter |
Value |
| Designation |
154P/Brewington |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2013-12-12T20:02:35.404800Z |
| Orbit solution date (soln_date, UTC) |
2025-04-11T15:12:51Z |
| Obs used |
2636 |
| NEO |
- |
| M1 |
11.400 |
| K1 |
15.750 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2015-04-27.0000000 |
| e |
0.67197880 |
| q (au) |
1.601379 |
| a (au) |
4.881937 |
| i (deg) |
17.885394 |
| Ω (om, deg) |
343.428377 |
| ω (w, deg) |
48.913742 |
| M (ma, deg) |
45.701350 |
Magnitude
Scatter + Global Linear
$$
M_a = (11.477 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
11.477 |
| n |
6.000 |
| gf |
0.800 |
| gb |
-0.500 |
| k |
0.875 |
| δ90 |
1.000 |
| 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 |
| 2024-05-25 |
2024-09-11 |
+15.8219 |
-4.860 |
| 2024-09-11 |
2025-03-06 |
+1.5067 |
-0.658 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
11:45:31.86 |
-02:50:05.1 |
HIP 57419 |
15.60 |
| 2026-09-20 12:00 |
11:45:50.50 |
-02:52:28.1 |
HIP 57419 |
10.57 |
| 2026-09-21 00:00 |
11:46:09.13 |
-02:54:51.2 |
HIP 57419 |
5.90 |
| 2026-09-21 12:00 |
11:46:27.74 |
-02:57:14.4 |
HIP 57419 |
3.55 |
| 2026-09-22 00:00 |
11:46:46.34 |
-02:59:37.5 |
HIP 57419 |
6.70 |
| 2026-09-22 12:00 |
11:47:04.93 |
-03:02:00.7 |
HIP 57519 |
5.08 |
| 2026-09-23 00:00 |
11:47:23.51 |
-03:04:24.0 |
HIP 57519 |
0.94 |
| 2026-09-23 12:00 |
11:47:42.07 |
-03:06:47.3 |
HIP 57519 |
5.51 |
| 2026-09-24 00:00 |
11:48:00.61 |
-03:09:10.6 |
HIP 57593 |
8.20 |
| 2026-09-24 12:00 |
11:48:19.14 |
-03:11:33.9 |
HIP 57593 |
3.28 |
| 2026-09-25 00:00 |
11:48:37.66 |
-03:13:57.3 |
HIP 57593 |
2.89 |
| 2026-09-25 12:00 |
11:48:56.15 |
-03:16:20.7 |
HIP 57609 |
6.40 |
| 2026-09-26 00:00 |
11:49:14.63 |
-03:18:44.0 |
HIP 57609 |
11.29 |
| 2026-09-26 12:00 |
11:49:33.10 |
-03:21:07.5 |
HIP 57609 |
16.36 |
| 2026-09-27 00:00 |
11:49:51.54 |
-03:23:30.9 |
HIP 57609 |
21.49 |
| 2026-09-27 12:00 |
11:50:09.97 |
-03:25:54.3 |
HIP 57609 |
26.63 |
| 2026-09-28 00:00 |
11:50:28.38 |
-03:28:17.7 |
HIP 57609 |
31.78 |
| 2026-09-28 12:00 |
11:50:46.77 |
-03:30:41.1 |
HIP 57609 |
36.94 |
| 2026-09-29 00:00 |
11:51:05.14 |
-03:33:04.6 |
HIP 57972 |
40.74 |
| 2026-09-29 12:00 |
11:51:23.48 |
-03:35:28.0 |
HIP 57972 |
35.57 |
| 2026-09-30 00:00 |
11:51:41.81 |
-03:37:51.4 |
HIP 57972 |
30.42 |
| 2026-09-30 12:00 |
11:52:00.12 |
-03:40:14.8 |
HIP 57972 |
25.27 |
| 2026-10-01 00:00 |
11:52:18.40 |
-03:42:38.2 |
HIP 57972 |
20.13 |
| 2026-10-01 12:00 |
11:52:36.66 |
-03:45:01.6 |
HIP 57972 |
14.99 |
| 2026-10-02 00:00 |
11:52:54.90 |
-03:47:24.9 |
HIP 57972 |
9.88 |
| 2026-10-02 12:00 |
11:53:13.11 |
-03:49:48.2 |
HIP 57972 |
4.82 |
| 2026-10-03 00:00 |
11:53:31.30 |
-03:52:11.5 |
HIP 57972 |
1.25 |
| 2026-10-03 12:00 |
11:53:49.46 |
-03:54:34.8 |
HIP 57972 |
5.69 |
| 2026-10-04 00:00 |
11:54:07.60 |
-03:56:58.0 |
HIP 57972 |
10.75 |
| 2026-10-04 12:00 |
11:54:25.71 |
-03:59:21.2 |
HIP 58007 |
15.26 |
| 2026-10-05 00:00 |
11:54:43.80 |
-04:01:44.3 |
HIP 58007 |
19.89 |
| 2026-10-05 12:00 |
11:55:01.86 |
-04:04:07.4 |
HIP 58197 |
17.42 |
| 2026-10-06 00:00 |
11:55:19.89 |
-04:06:30.5 |
HIP 58197 |
12.43 |
| 2026-10-06 12:00 |
11:55:37.89 |
-04:08:53.5 |
HIP 58197 |
7.60 |
| 2026-10-07 00:00 |
11:55:55.86 |
-04:11:16.4 |
HIP 58197 |
3.54 |
| 2026-10-07 12:00 |
11:56:13.80 |
-04:13:39.2 |
HIP 58197 |
4.34 |
| 2026-10-08 00:00 |
11:56:31.71 |
-04:16:02.0 |
HIP 58197 |
8.74 |
| 2026-10-08 12:00 |
11:56:49.59 |
-04:18:24.8 |
HIP 58282 |
11.97 |
| 2026-10-09 00:00 |
11:57:07.44 |
-04:20:47.4 |
HIP 58282 |
13.22 |
| 2026-10-09 12:00 |
11:57:25.25 |
-04:23:10.0 |
HIP 58368 |
10.42 |
| 2026-10-10 00:00 |
11:57:43.03 |
-04:25:32.4 |
HIP 58368 |
6.80 |
| 2026-10-10 12:00 |
11:58:00.77 |
-04:27:54.8 |
HIP 58368 |
5.88 |
| 2026-10-11 00:00 |
11:58:18.48 |
-04:30:17.1 |
HIP 58368 |
8.55 |