| Parameter |
Value |
| Designation |
105P/Singer Brewster |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2012-02-25T23:41:27.876480Z |
| Orbit solution date (soln_date, UTC) |
2025-10-06T22:38:31Z |
| Obs used |
898 |
| NEO |
- |
| M1 |
13.700 |
| K1 |
10.250 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2013-09-15.0000000 |
| e |
0.40905926 |
| q (au) |
2.050165 |
| a (au) |
3.469324 |
| i (deg) |
9.171690 |
| Ω (om, deg) |
192.411758 |
| ω (w, deg) |
46.610938 |
| M (ma, deg) |
86.482795 |
Magnitude
Scatter + Global Linear
$$
M_a = (18.483 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
18.483 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.677 |
| k |
0.800 |
| δ90 |
10.000 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
00:29:24.31 |
+05:16:22.8 |
HIP 2369 |
13.69 |
| 2026-05-12 12:00 |
00:29:54.33 |
+05:19:11.9 |
HIP 2369 |
5.72 |
| 2026-05-13 00:00 |
00:30:24.24 |
+05:22:00.3 |
HIP 2369 |
2.33 |
| 2026-05-13 12:00 |
00:30:54.07 |
+05:24:48.1 |
HIP 2369 |
10.21 |
| 2026-05-14 00:00 |
00:31:23.79 |
+05:27:35.2 |
HIP 2369 |
18.11 |
| 2026-05-14 12:00 |
00:31:53.42 |
+05:30:21.5 |
HIP 2369 |
25.98 |
| 2026-05-15 00:00 |
00:32:22.95 |
+05:33:07.2 |
HIP 2477 |
27.87 |
| 2026-05-15 12:00 |
00:32:52.38 |
+05:35:52.2 |
HIP 2688 |
28.69 |
| 2026-05-16 00:00 |
00:33:21.71 |
+05:38:36.5 |
HIP 2688 |
22.14 |
| 2026-05-16 12:00 |
00:33:50.94 |
+05:41:20.0 |
HIP 2688 |
16.70 |
| 2026-05-17 00:00 |
00:34:20.07 |
+05:44:02.9 |
HIP 2688 |
13.74 |
| 2026-05-17 12:00 |
00:34:49.09 |
+05:46:45.0 |
HIP 2688 |
14.76 |
| 2026-05-18 00:00 |
00:35:18.02 |
+05:49:26.4 |
HIP 2688 |
19.11 |
| 2026-05-18 12:00 |
00:35:46.84 |
+05:52:07.0 |
HIP 2688 |
25.08 |
| 2026-05-19 00:00 |
00:36:15.55 |
+05:54:46.9 |
HIP 2991 |
26.59 |
| 2026-05-19 12:00 |
00:36:44.16 |
+05:57:26.0 |
HIP 2991 |
20.28 |
| 2026-05-20 00:00 |
00:37:12.66 |
+06:00:04.4 |
HIP 2991 |
15.20 |
| 2026-05-20 12:00 |
00:37:41.06 |
+06:02:42.0 |
HIP 2991 |
12.87 |
| 2026-05-21 00:00 |
00:38:09.35 |
+06:05:18.9 |
HIP 3033 |
7.40 |
| 2026-05-21 12:00 |
00:38:37.53 |
+06:07:55.0 |
HIP 3033 |
6.64 |
| 2026-05-22 00:00 |
00:39:05.61 |
+06:10:30.3 |
HIP 3033 |
12.02 |
| 2026-05-22 12:00 |
00:39:33.57 |
+06:13:04.8 |
HIP 3033 |
18.83 |
| 2026-05-23 00:00 |
00:40:01.43 |
+06:15:38.5 |
HIP 3033 |
25.94 |
| 2026-05-23 12:00 |
00:40:29.17 |
+06:18:11.5 |
HIP 3033 |
33.14 |
| 2026-05-24 00:00 |
00:40:56.80 |
+06:20:43.6 |
HIP 3393 |
37.19 |
| 2026-05-24 12:00 |
00:41:24.32 |
+06:23:15.0 |
HIP 3393 |
29.90 |
| 2026-05-25 00:00 |
00:41:51.73 |
+06:25:45.6 |
HIP 3393 |
22.64 |
| 2026-05-25 12:00 |
00:42:19.03 |
+06:28:15.3 |
HIP 3393 |
15.42 |
| 2026-05-26 00:00 |
00:42:46.21 |
+06:30:44.3 |
HIP 3393 |
8.24 |
| 2026-05-26 12:00 |
00:43:13.28 |
+06:33:12.4 |
HIP 3393 |
1.24 |
| 2026-05-27 00:00 |
00:43:40.23 |
+06:35:39.7 |
HIP 3393 |
6.11 |
| 2026-05-27 12:00 |
00:44:07.07 |
+06:38:06.2 |
HIP 3393 |
13.19 |
| 2026-05-28 00:00 |
00:44:33.79 |
+06:40:31.9 |
HIP 3393 |
20.25 |
| 2026-05-28 12:00 |
00:45:00.40 |
+06:42:56.7 |
HIP 3393 |
27.28 |
| 2026-05-29 00:00 |
00:45:26.89 |
+06:45:20.7 |
HIP 3697 |
29.00 |
| 2026-05-29 12:00 |
00:45:53.26 |
+06:47:43.8 |
HIP 3697 |
22.67 |
| 2026-05-30 00:00 |
00:46:19.51 |
+06:50:06.1 |
HIP 3697 |
16.89 |
| 2026-05-30 12:00 |
00:46:45.64 |
+06:52:27.6 |
HIP 3697 |
12.37 |
| 2026-05-31 00:00 |
00:47:11.65 |
+06:54:48.2 |
HIP 3697 |
10.76 |
| 2026-05-31 12:00 |
00:47:37.54 |
+06:57:07.9 |
HIP 3697 |
13.14 |
| 2026-06-01 00:00 |
00:48:03.31 |
+06:59:26.8 |
HIP 3697 |
17.93 |
| 2026-06-01 12:00 |
00:48:28.96 |
+07:01:44.8 |
HIP 3760 |
16.50 |
| 2026-06-02 00:00 |
00:48:54.48 |
+07:04:01.9 |
HIP 3760 |
16.73 |