| Parameter |
Value |
| Designation |
C/1997 O1 (Tilbrook) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1997-07-13T10:06:45.694080Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:51Z |
| Obs used |
115 |
| NEO |
- |
| M1 |
8.000 |
| K1 |
10.000 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1997-09-25.0000000 |
| e |
0.98423544 |
| q (au) |
1.371814 |
| a (au) |
87.018855 |
| i (deg) |
115.802396 |
| Ω (om, deg) |
231.245985 |
| ω (w, deg) |
336.189199 |
| M (ma, deg) |
0.089338 |
Magnitude
Scatter + Global Linear
$$
M_a = (6.718 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
6.718 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.998 |
| k |
1.000 |
| 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 |
04:04:08.03 |
+56:31:51.2 |
HIP 19034 |
13.38 |
| 2026-05-12 12:00 |
04:04:12.15 |
+56:31:51.0 |
HIP 19034 |
13.22 |
| 2026-05-13 00:00 |
04:04:16.28 |
+56:31:50.9 |
HIP 19034 |
13.07 |
| 2026-05-13 12:00 |
04:04:20.41 |
+56:31:51.0 |
HIP 19034 |
12.94 |
| 2026-05-14 00:00 |
04:04:24.56 |
+56:31:51.3 |
HIP 19034 |
12.84 |
| 2026-05-14 12:00 |
04:04:28.70 |
+56:31:51.8 |
HIP 19034 |
12.75 |
| 2026-05-15 00:00 |
04:04:32.86 |
+56:31:52.5 |
HIP 19034 |
12.69 |
| 2026-05-15 12:00 |
04:04:37.01 |
+56:31:53.3 |
HIP 19034 |
12.65 |
| 2026-05-16 00:00 |
04:04:41.18 |
+56:31:54.3 |
HIP 19034 |
12.63 |
| 2026-05-16 12:00 |
04:04:45.35 |
+56:31:55.5 |
HIP 19034 |
12.64 |
| 2026-05-17 00:00 |
04:04:49.52 |
+56:31:56.8 |
HIP 19034 |
12.66 |
| 2026-05-17 12:00 |
04:04:53.70 |
+56:31:58.4 |
HIP 19034 |
12.72 |
| 2026-05-18 00:00 |
04:04:57.88 |
+56:32:00.1 |
HIP 19034 |
12.79 |
| 2026-05-18 12:00 |
04:05:02.06 |
+56:32:02.0 |
HIP 19034 |
12.89 |
| 2026-05-19 00:00 |
04:05:06.25 |
+56:32:04.0 |
HIP 19034 |
13.01 |
| 2026-05-19 12:00 |
04:05:10.44 |
+56:32:06.3 |
HIP 19034 |
13.15 |
| 2026-05-20 00:00 |
04:05:14.64 |
+56:32:08.7 |
HIP 19034 |
13.31 |
| 2026-05-20 12:00 |
04:05:18.83 |
+56:32:11.2 |
HIP 19034 |
13.49 |
| 2026-05-21 00:00 |
04:05:23.03 |
+56:32:14.0 |
HIP 19034 |
13.70 |
| 2026-05-21 12:00 |
04:05:27.23 |
+56:32:16.9 |
HIP 19034 |
13.92 |
| 2026-05-22 00:00 |
04:05:31.43 |
+56:32:20.0 |
HIP 19034 |
14.16 |
| 2026-05-22 12:00 |
04:05:35.64 |
+56:32:23.3 |
HIP 19034 |
14.41 |
| 2026-05-23 00:00 |
04:05:39.84 |
+56:32:26.7 |
HIP 19034 |
14.68 |
| 2026-05-23 12:00 |
04:05:44.05 |
+56:32:30.3 |
HIP 19034 |
14.97 |
| 2026-05-24 00:00 |
04:05:48.25 |
+56:32:34.1 |
HIP 19034 |
15.27 |
| 2026-05-24 12:00 |
04:05:52.46 |
+56:32:38.0 |
HIP 19034 |
15.59 |
| 2026-05-25 00:00 |
04:05:56.66 |
+56:32:42.1 |
HIP 19224 |
15.54 |
| 2026-05-25 12:00 |
04:06:00.87 |
+56:32:46.4 |
HIP 19224 |
15.11 |
| 2026-05-26 00:00 |
04:06:05.07 |
+56:32:50.8 |
HIP 19224 |
14.68 |
| 2026-05-26 12:00 |
04:06:09.28 |
+56:32:55.4 |
HIP 19224 |
14.27 |
| 2026-05-27 00:00 |
04:06:13.48 |
+56:33:00.2 |
HIP 19224 |
13.86 |
| 2026-05-27 12:00 |
04:06:17.68 |
+56:33:05.2 |
HIP 19224 |
13.46 |
| 2026-05-28 00:00 |
04:06:21.88 |
+56:33:10.3 |
HIP 19224 |
13.08 |
| 2026-05-28 12:00 |
04:06:26.08 |
+56:33:15.5 |
HIP 19224 |
12.71 |
| 2026-05-29 00:00 |
04:06:30.28 |
+56:33:21.0 |
HIP 19224 |
12.35 |
| 2026-05-29 12:00 |
04:06:34.47 |
+56:33:26.6 |
HIP 19224 |
12.01 |
| 2026-05-30 00:00 |
04:06:38.66 |
+56:33:32.3 |
HIP 19224 |
11.69 |
| 2026-05-30 12:00 |
04:06:42.85 |
+56:33:38.3 |
HIP 19224 |
11.38 |
| 2026-05-31 00:00 |
04:06:47.03 |
+56:33:44.4 |
HIP 19224 |
11.09 |
| 2026-05-31 12:00 |
04:06:51.21 |
+56:33:50.6 |
HIP 19224 |
10.83 |
| 2026-06-01 00:00 |
04:06:55.39 |
+56:33:57.0 |
HIP 19224 |
10.59 |
| 2026-06-01 12:00 |
04:06:59.57 |
+56:34:03.6 |
HIP 19224 |
10.37 |
| 2026-06-02 00:00 |
04:07:03.74 |
+56:34:10.3 |
HIP 19224 |
10.18 |