| Parameter |
Value |
| Designation |
84P/Giclas |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2013-07-23T01:44:13.433280Z |
| Orbit solution date (soln_date, UTC) |
2021-03-29T10:00:09Z |
| Obs used |
1745 |
| NEO |
- |
| M1 |
14.200 |
| K1 |
6.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2011-11-29.0000000 |
| e |
0.49446792 |
| q (au) |
1.840491 |
| a (au) |
3.640700 |
| i (deg) |
7.284294 |
| Ω (om, deg) |
112.389336 |
| ω (w, deg) |
276.404790 |
| M (ma, deg) |
274.576888 |
Magnitude
Scatter + Global Linear
$$
M_a = (9.993 + 5.836\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
9.993 |
| n |
5.836 |
| gf |
1.000 |
| gb |
-0.896 |
| 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
Finding Chart
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-03-26 00:00 |
20:01:02.04 |
-19:40:46.9 |
HIP 98489 |
12.91 |
| 2026-03-26 12:00 |
20:01:38.53 |
-19:39:31.9 |
HIP 98489 |
19.85 |
| 2026-03-27 00:00 |
20:02:14.91 |
-19:38:16.8 |
HIP 98489 |
27.77 |
| 2026-03-27 12:00 |
20:02:51.20 |
-19:37:01.7 |
HIP 98634 |
33.24 |
| 2026-03-28 00:00 |
20:03:27.40 |
-19:35:46.5 |
HIP 98634 |
36.10 |
| 2026-03-28 12:00 |
20:04:03.50 |
-19:34:31.3 |
HIP 98634 |
40.61 |
| 2026-03-29 00:00 |
20:04:39.50 |
-19:33:16.0 |
HIP 99096 |
35.22 |
| 2026-03-29 12:00 |
20:05:15.40 |
-19:32:00.7 |
HIP 99096 |
26.71 |
| 2026-03-30 00:00 |
20:05:51.20 |
-19:30:45.4 |
HIP 99096 |
18.24 |
| 2026-03-30 12:00 |
20:06:26.90 |
-19:29:30.1 |
HIP 99096 |
9.92 |
| 2026-03-31 00:00 |
20:07:02.50 |
-19:28:14.8 |
HIP 99096 |
2.94 |
| 2026-03-31 12:00 |
20:07:38.00 |
-19:26:59.5 |
HIP 99096 |
7.91 |
| 2026-04-01 00:00 |
20:08:13.40 |
-19:25:44.2 |
HIP 99118 |
15.07 |
| 2026-04-01 12:00 |
20:08:48.69 |
-19:24:28.9 |
HIP 99391 |
22.87 |
| 2026-04-02 00:00 |
20:09:23.88 |
-19:23:13.7 |
HIP 99391 |
14.53 |
| 2026-04-02 12:00 |
20:09:58.96 |
-19:21:58.5 |
HIP 99391 |
6.33 |
| 2026-04-03 00:00 |
20:10:33.93 |
-19:20:43.3 |
HIP 99391 |
3.02 |
| 2026-04-03 12:00 |
20:11:08.80 |
-19:19:28.3 |
HIP 99391 |
10.81 |
| 2026-04-04 00:00 |
20:11:43.56 |
-19:18:13.3 |
HIP 99391 |
19.03 |
| 2026-04-04 12:00 |
20:12:18.21 |
-19:16:58.4 |
HIP 99391 |
27.27 |
| 2026-04-05 00:00 |
20:12:52.75 |
-19:15:43.5 |
HIP 99782 |
26.18 |
| 2026-04-05 12:00 |
20:13:27.18 |
-19:14:28.8 |
HIP 99782 |
17.97 |
| 2026-04-06 00:00 |
20:14:01.49 |
-19:13:14.2 |
HIP 99782 |
9.78 |
| 2026-04-06 12:00 |
20:14:35.69 |
-19:11:59.7 |
HIP 99782 |
1.73 |
| 2026-04-07 00:00 |
20:15:09.78 |
-19:10:45.4 |
HIP 99782 |
6.59 |
| 2026-04-07 12:00 |
20:15:43.75 |
-19:09:31.2 |
HIP 99782 |
14.68 |
| 2026-04-08 00:00 |
20:16:17.60 |
-19:08:17.1 |
HIP 99782 |
22.77 |
| 2026-04-08 12:00 |
20:16:51.34 |
-19:07:03.2 |
HIP 100107 |
25.21 |
| 2026-04-09 00:00 |
20:17:24.96 |
-19:05:49.5 |
HIP 100107 |
19.01 |
| 2026-04-09 12:00 |
20:17:58.45 |
-19:04:36.0 |
HIP 100107 |
14.71 |
| 2026-04-10 00:00 |
20:18:31.82 |
-19:03:22.7 |
HIP 100195 |
12.79 |
| 2026-04-10 12:00 |
20:19:05.07 |
-19:02:09.6 |
HIP 100195 |
6.61 |
| 2026-04-11 00:00 |
20:19:38.20 |
-19:00:56.8 |
HIP 100195 |
7.06 |
| 2026-04-11 12:00 |
20:20:11.20 |
-18:59:44.1 |
HIP 100195 |
13.45 |
| 2026-04-12 00:00 |
20:20:44.07 |
-18:58:31.7 |
HIP 100393 |
12.96 |
| 2026-04-12 12:00 |
20:21:16.82 |
-18:57:19.6 |
HIP 100393 |
8.11 |
| 2026-04-13 00:00 |
20:21:49.43 |
-18:56:07.7 |
HIP 100393 |
9.28 |
| 2026-04-13 12:00 |
20:22:21.92 |
-18:54:56.2 |
HIP 100393 |
15.08 |
| 2026-04-14 00:00 |
20:22:54.27 |
-18:53:44.9 |
HIP 100393 |
22.09 |
| 2026-04-14 12:00 |
20:23:26.48 |
-18:52:33.9 |
HIP 100393 |
29.44 |
| 2026-04-15 00:00 |
20:23:58.57 |
-18:51:23.3 |
HIP 100533 |
33.10 |
| 2026-04-15 12:00 |
20:24:30.51 |
-18:50:13.0 |
HIP 100770 |
29.03 |
| 2026-04-16 00:00 |
20:25:02.32 |
-18:49:03.0 |
HIP 100770 |
23.52 |