| 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) |
| 2026-07-29 00:00 |
04:13:27.19 |
+57:01:19.8 |
HIP 19522 |
21.65 |
| 2026-07-29 12:00 |
04:13:29.22 |
+57:01:39.6 |
HIP 19522 |
21.80 |
| 2026-07-30 00:00 |
04:13:31.23 |
+57:01:59.3 |
HIP 19522 |
21.96 |
| 2026-07-30 12:00 |
04:13:33.20 |
+57:02:19.1 |
HIP 19522 |
22.11 |
| 2026-07-31 00:00 |
04:13:35.14 |
+57:02:39.0 |
HIP 19522 |
22.27 |
| 2026-07-31 12:00 |
04:13:37.06 |
+57:02:58.9 |
HIP 19522 |
22.44 |
| 2026-08-01 00:00 |
04:13:38.94 |
+57:03:18.8 |
HIP 19522 |
22.60 |
| 2026-08-01 12:00 |
04:13:40.78 |
+57:03:38.8 |
HIP 19522 |
22.77 |
| 2026-08-02 00:00 |
04:13:42.60 |
+57:03:58.8 |
HIP 19522 |
22.94 |
| 2026-08-02 12:00 |
04:13:44.39 |
+57:04:18.9 |
HIP 19522 |
23.11 |
| 2026-08-03 00:00 |
04:13:46.14 |
+57:04:39.0 |
HIP 19522 |
23.28 |
| 2026-08-03 12:00 |
04:13:47.86 |
+57:04:59.2 |
HIP 19522 |
23.45 |
| 2026-08-04 00:00 |
04:13:49.55 |
+57:05:19.4 |
HIP 19522 |
23.63 |
| 2026-08-04 12:00 |
04:13:51.20 |
+57:05:39.6 |
HIP 19522 |
23.80 |
| 2026-08-05 00:00 |
04:13:52.82 |
+57:05:59.9 |
HIP 19823 |
23.55 |
| 2026-08-05 12:00 |
04:13:54.41 |
+57:06:20.2 |
HIP 19823 |
23.15 |
| 2026-08-06 00:00 |
04:13:55.97 |
+57:06:40.5 |
HIP 19823 |
22.76 |
| 2026-08-06 12:00 |
04:13:57.50 |
+57:07:00.8 |
HIP 19823 |
22.36 |
| 2026-08-07 00:00 |
04:13:58.99 |
+57:07:21.2 |
HIP 19823 |
21.97 |
| 2026-08-07 12:00 |
04:14:00.44 |
+57:07:41.6 |
HIP 19823 |
21.58 |
| 2026-08-08 00:00 |
04:14:01.86 |
+57:08:02.1 |
HIP 19823 |
21.19 |
| 2026-08-08 12:00 |
04:14:03.25 |
+57:08:22.5 |
HIP 19823 |
20.81 |
| 2026-08-09 00:00 |
04:14:04.61 |
+57:08:43.0 |
HIP 19823 |
20.42 |
| 2026-08-09 12:00 |
04:14:05.93 |
+57:09:03.5 |
HIP 19823 |
20.04 |
| 2026-08-10 00:00 |
04:14:07.22 |
+57:09:24.1 |
HIP 19823 |
19.65 |
| 2026-08-10 12:00 |
04:14:08.47 |
+57:09:44.6 |
HIP 19823 |
19.27 |
| 2026-08-11 00:00 |
04:14:09.68 |
+57:10:05.2 |
HIP 19823 |
18.89 |
| 2026-08-11 12:00 |
04:14:10.87 |
+57:10:25.8 |
HIP 19823 |
18.52 |
| 2026-08-12 00:00 |
04:14:12.01 |
+57:10:46.3 |
HIP 19823 |
18.14 |
| 2026-08-12 12:00 |
04:14:13.13 |
+57:11:07.0 |
HIP 19823 |
17.77 |
| 2026-08-13 00:00 |
04:14:14.20 |
+57:11:27.6 |
HIP 19823 |
17.39 |
| 2026-08-13 12:00 |
04:14:15.25 |
+57:11:48.2 |
HIP 19823 |
17.02 |
| 2026-08-14 00:00 |
04:14:16.25 |
+57:12:08.8 |
HIP 19823 |
16.65 |
| 2026-08-14 12:00 |
04:14:17.22 |
+57:12:29.5 |
HIP 19823 |
16.28 |
| 2026-08-15 00:00 |
04:14:18.16 |
+57:12:50.1 |
HIP 19823 |
15.92 |
| 2026-08-15 12:00 |
04:14:19.06 |
+57:13:10.8 |
HIP 19823 |
15.55 |
| 2026-08-16 00:00 |
04:14:19.92 |
+57:13:31.4 |
HIP 19823 |
15.19 |
| 2026-08-16 12:00 |
04:14:20.75 |
+57:13:52.1 |
HIP 19823 |
14.83 |
| 2026-08-17 00:00 |
04:14:21.54 |
+57:14:12.7 |
HIP 19823 |
14.47 |
| 2026-08-17 12:00 |
04:14:22.29 |
+57:14:33.4 |
HIP 19823 |
14.11 |
| 2026-08-18 00:00 |
04:14:23.01 |
+57:14:54.0 |
HIP 19823 |
13.75 |
| 2026-08-18 12:00 |
04:14:23.69 |
+57:15:14.7 |
HIP 19823 |
13.40 |
| 2026-08-19 00:00 |
04:14:24.34 |
+57:15:35.3 |
HIP 19823 |
13.05 |