| Parameter |
Value |
| Designation |
84P/Giclas |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2020-06-03T07:12:09.486720Z |
| Orbit solution date (soln_date, UTC) |
2026-09-21T09:58:31Z |
| Obs used |
1279 |
| NEO |
- |
| M1 |
11.800 |
| K1 |
13.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2019-02-07.0000000 |
| e |
0.51601034 |
| q (au) |
1.721926 |
| a (au) |
3.557774 |
| i (deg) |
7.539110 |
| Ω (om, deg) |
108.207478 |
| ω (w, deg) |
281.293621 |
| M (ma, deg) |
289.164035 |
Magnitude
Scatter + Global Linear
$$
M_a = (12.339 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
12.339 |
| n |
6.000 |
| gf |
0.999 |
| gb |
-0.600 |
| k |
0.852 |
| δ90 |
9.187 |
| 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) |
| 2026-09-20 00:00 |
20:15:20.98 |
-26:28:42.8 |
HIP 99884 |
19.83 |
| 2026-09-20 12:00 |
20:15:24.74 |
-26:29:04.0 |
HIP 99884 |
19.19 |
| 2026-09-21 00:00 |
20:15:29.05 |
-26:29:22.7 |
HIP 99884 |
18.57 |
| 2026-09-21 12:00 |
20:15:33.91 |
-26:29:39.1 |
HIP 99884 |
17.99 |
| 2026-09-22 00:00 |
20:15:39.33 |
-26:29:53.0 |
HIP 99884 |
17.48 |
| 2026-09-22 12:00 |
20:15:45.29 |
-26:30:04.6 |
HIP 99884 |
17.07 |
| 2026-09-23 00:00 |
20:15:51.80 |
-26:30:13.8 |
HIP 99884 |
16.79 |
| 2026-09-23 12:00 |
20:15:58.87 |
-26:30:20.7 |
HIP 99884 |
16.68 |
| 2026-09-24 00:00 |
20:16:06.48 |
-26:30:25.2 |
HIP 99884 |
16.77 |
| 2026-09-24 12:00 |
20:16:14.64 |
-26:30:27.3 |
HIP 99884 |
17.10 |
| 2026-09-25 00:00 |
20:16:23.35 |
-26:30:27.1 |
HIP 99884 |
17.70 |
| 2026-09-25 12:00 |
20:16:32.60 |
-26:30:24.6 |
HIP 99884 |
18.57 |
| 2026-09-26 00:00 |
20:16:42.40 |
-26:30:19.7 |
HIP 99884 |
19.72 |
| 2026-09-26 12:00 |
20:16:52.74 |
-26:30:12.5 |
HIP 99884 |
21.14 |
| 2026-09-27 00:00 |
20:17:03.62 |
-26:30:03.0 |
HIP 99884 |
22.82 |
| 2026-09-27 12:00 |
20:17:15.04 |
-26:29:51.2 |
HIP 99884 |
24.74 |
| 2026-09-28 00:00 |
20:17:27.00 |
-26:29:37.0 |
HIP 99884 |
26.88 |
| 2026-09-28 12:00 |
20:17:39.50 |
-26:29:20.6 |
HIP 100182 |
28.69 |
| 2026-09-29 00:00 |
20:17:52.54 |
-26:29:01.9 |
HIP 100182 |
26.38 |
| 2026-09-29 12:00 |
20:18:06.11 |
-26:28:40.9 |
HIP 100182 |
24.09 |
| 2026-09-30 00:00 |
20:18:20.22 |
-26:28:17.6 |
HIP 100182 |
21.90 |
| 2026-09-30 12:00 |
20:18:34.86 |
-26:27:52.0 |
HIP 100182 |
19.88 |
| 2026-10-01 00:00 |
20:18:50.03 |
-26:27:24.2 |
HIP 100182 |
18.18 |
| 2026-10-01 12:00 |
20:19:05.73 |
-26:26:54.0 |
HIP 100182 |
16.95 |
| 2026-10-02 00:00 |
20:19:21.96 |
-26:26:21.6 |
HIP 100182 |
16.39 |
| 2026-10-02 12:00 |
20:19:38.72 |
-26:25:46.9 |
HIP 100182 |
16.65 |
| 2026-10-03 00:00 |
20:19:56.00 |
-26:25:10.0 |
HIP 100182 |
17.76 |
| 2026-10-03 12:00 |
20:20:13.81 |
-26:24:30.7 |
HIP 100311 |
16.71 |
| 2026-10-04 00:00 |
20:20:32.13 |
-26:23:49.2 |
HIP 100311 |
15.01 |
| 2026-10-04 12:00 |
20:20:50.98 |
-26:23:05.5 |
HIP 100311 |
14.35 |
| 2026-10-05 00:00 |
20:21:10.35 |
-26:22:19.4 |
HIP 100311 |
14.95 |
| 2026-10-05 12:00 |
20:21:30.24 |
-26:21:31.1 |
HIP 100311 |
16.79 |
| 2026-10-06 00:00 |
20:21:50.64 |
-26:20:40.6 |
HIP 100474 |
14.36 |
| 2026-10-06 12:00 |
20:22:11.56 |
-26:19:47.7 |
HIP 100474 |
11.13 |
| 2026-10-07 00:00 |
20:22:32.99 |
-26:18:52.6 |
HIP 100474 |
9.30 |
| 2026-10-07 12:00 |
20:22:54.93 |
-26:17:55.3 |
HIP 100474 |
9.87 |
| 2026-10-08 00:00 |
20:23:17.38 |
-26:16:55.6 |
HIP 100474 |
12.67 |
| 2026-10-08 12:00 |
20:23:40.33 |
-26:15:53.7 |
HIP 100474 |
16.72 |
| 2026-10-09 00:00 |
20:24:03.79 |
-26:14:49.6 |
HIP 100474 |
21.40 |
| 2026-10-09 12:00 |
20:24:27.76 |
-26:13:43.2 |
HIP 100663 |
23.79 |
| 2026-10-10 00:00 |
20:24:52.22 |
-26:12:34.5 |
HIP 100663 |
22.80 |
| 2026-10-10 12:00 |
20:25:17.18 |
-26:11:23.5 |
HIP 100765 |
23.09 |
| 2026-10-11 00:00 |
20:25:42.63 |
-26:10:10.3 |
HIP 100765 |
23.25 |