| 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 |
-1.000 |
| 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) |
| 2026-09-20 00:00 |
04:13:48.07 |
+57:36:11.2 |
HIP 19823 |
13.09 |
| 2026-09-20 12:00 |
04:13:46.28 |
+57:36:28.1 |
HIP 19823 |
13.45 |
| 2026-09-21 00:00 |
04:13:44.46 |
+57:36:44.9 |
HIP 19823 |
13.82 |
| 2026-09-21 12:00 |
04:13:42.60 |
+57:37:01.5 |
HIP 19823 |
14.19 |
| 2026-09-22 00:00 |
04:13:40.71 |
+57:37:18.0 |
HIP 19823 |
14.56 |
| 2026-09-22 12:00 |
04:13:38.77 |
+57:37:34.5 |
HIP 19823 |
14.94 |
| 2026-09-23 00:00 |
04:13:36.81 |
+57:37:50.8 |
HIP 19823 |
15.32 |
| 2026-09-23 12:00 |
04:13:34.80 |
+57:38:07.0 |
HIP 19823 |
15.69 |
| 2026-09-24 00:00 |
04:13:32.77 |
+57:38:23.1 |
HIP 19823 |
16.08 |
| 2026-09-24 12:00 |
04:13:30.69 |
+57:38:39.0 |
HIP 19823 |
16.46 |
| 2026-09-25 00:00 |
04:13:28.58 |
+57:38:54.9 |
HIP 19823 |
16.85 |
| 2026-09-25 12:00 |
04:13:26.44 |
+57:39:10.6 |
HIP 19823 |
17.24 |
| 2026-09-26 00:00 |
04:13:24.26 |
+57:39:26.2 |
HIP 19823 |
17.63 |
| 2026-09-26 12:00 |
04:13:22.04 |
+57:39:41.6 |
HIP 19823 |
18.02 |
| 2026-09-27 00:00 |
04:13:19.79 |
+57:39:57.0 |
HIP 19823 |
18.41 |
| 2026-09-27 12:00 |
04:13:17.50 |
+57:40:12.2 |
HIP 19823 |
18.81 |
| 2026-09-28 00:00 |
04:13:15.18 |
+57:40:27.3 |
HIP 19823 |
19.21 |
| 2026-09-28 12:00 |
04:13:12.83 |
+57:40:42.2 |
HIP 19823 |
19.61 |
| 2026-09-29 00:00 |
04:13:10.44 |
+57:40:57.1 |
HIP 19823 |
20.01 |
| 2026-09-29 12:00 |
04:13:08.02 |
+57:41:11.8 |
HIP 19823 |
20.42 |
| 2026-09-30 00:00 |
04:13:05.56 |
+57:41:26.3 |
HIP 19823 |
20.83 |
| 2026-09-30 12:00 |
04:13:03.06 |
+57:41:40.7 |
HIP 19823 |
21.23 |
| 2026-10-01 00:00 |
04:13:00.54 |
+57:41:55.0 |
HIP 19823 |
21.64 |
| 2026-10-01 12:00 |
04:12:57.98 |
+57:42:09.2 |
HIP 19488 |
21.82 |
| 2026-10-02 00:00 |
04:12:55.38 |
+57:42:23.2 |
HIP 19488 |
21.40 |
| 2026-10-02 12:00 |
04:12:52.76 |
+57:42:37.0 |
HIP 19488 |
20.99 |
| 2026-10-03 00:00 |
04:12:50.10 |
+57:42:50.8 |
HIP 19488 |
20.57 |
| 2026-10-03 12:00 |
04:12:47.40 |
+57:43:04.3 |
HIP 19488 |
20.15 |
| 2026-10-04 00:00 |
04:12:44.67 |
+57:43:17.8 |
HIP 19488 |
19.73 |
| 2026-10-04 12:00 |
04:12:41.91 |
+57:43:31.1 |
HIP 19488 |
19.30 |
| 2026-10-05 00:00 |
04:12:39.12 |
+57:43:44.2 |
HIP 19488 |
18.87 |
| 2026-10-05 12:00 |
04:12:36.29 |
+57:43:57.2 |
HIP 19488 |
18.44 |
| 2026-10-06 00:00 |
04:12:33.43 |
+57:44:10.0 |
HIP 19488 |
18.01 |
| 2026-10-06 12:00 |
04:12:30.54 |
+57:44:22.7 |
HIP 19488 |
17.57 |
| 2026-10-07 00:00 |
04:12:27.62 |
+57:44:35.2 |
HIP 19488 |
17.13 |
| 2026-10-07 12:00 |
04:12:24.67 |
+57:44:47.6 |
HIP 19488 |
16.69 |
| 2026-10-08 00:00 |
04:12:21.68 |
+57:44:59.8 |
HIP 19488 |
16.24 |
| 2026-10-08 12:00 |
04:12:18.66 |
+57:45:11.9 |
HIP 19488 |
15.79 |
| 2026-10-09 00:00 |
04:12:15.61 |
+57:45:23.8 |
HIP 19488 |
15.34 |
| 2026-10-09 12:00 |
04:12:12.53 |
+57:45:35.5 |
HIP 19488 |
14.88 |
| 2026-10-10 00:00 |
04:12:09.42 |
+57:45:47.1 |
HIP 19488 |
14.43 |
| 2026-10-10 12:00 |
04:12:06.27 |
+57:45:58.5 |
HIP 19488 |
13.97 |
| 2026-10-11 00:00 |
04:12:03.10 |
+57:46:09.8 |
HIP 19488 |
13.51 |