| 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) |
| 2026-05-12 00:00 |
20:48:55.60 |
-18:01:42.9 |
HIP 102780 |
5.95 |
| 2026-05-12 12:00 |
20:49:18.24 |
-18:01:10.2 |
HIP 102780 |
1.12 |
| 2026-05-13 00:00 |
20:49:40.67 |
-18:00:38.6 |
HIP 102780 |
5.02 |
| 2026-05-13 12:00 |
20:50:02.88 |
-18:00:08.1 |
HIP 102780 |
10.26 |
| 2026-05-14 00:00 |
20:50:24.86 |
-17:59:38.8 |
HIP 102780 |
15.50 |
| 2026-05-14 12:00 |
20:50:46.63 |
-17:59:10.6 |
HIP 102780 |
20.68 |
| 2026-05-15 00:00 |
20:51:08.17 |
-17:58:43.6 |
HIP 102780 |
25.82 |
| 2026-05-15 12:00 |
20:51:29.48 |
-17:58:17.8 |
HIP 102780 |
30.90 |
| 2026-05-16 00:00 |
20:51:50.57 |
-17:57:53.2 |
HIP 102780 |
35.92 |
| 2026-05-16 12:00 |
20:52:11.42 |
-17:57:29.9 |
HIP 103226 |
37.27 |
| 2026-05-17 00:00 |
20:52:32.04 |
-17:57:07.8 |
HIP 103226 |
32.35 |
| 2026-05-17 12:00 |
20:52:52.43 |
-17:56:46.9 |
HIP 103226 |
27.49 |
| 2026-05-18 00:00 |
20:53:12.58 |
-17:56:27.3 |
HIP 103226 |
22.69 |
| 2026-05-18 12:00 |
20:53:32.49 |
-17:56:09.1 |
HIP 103226 |
17.94 |
| 2026-05-19 00:00 |
20:53:52.17 |
-17:55:52.1 |
HIP 103226 |
13.25 |
| 2026-05-19 12:00 |
20:54:11.60 |
-17:55:36.4 |
HIP 103226 |
8.63 |
| 2026-05-20 00:00 |
20:54:30.79 |
-17:55:22.1 |
HIP 103226 |
4.06 |
| 2026-05-20 12:00 |
20:54:49.74 |
-17:55:09.2 |
HIP 103226 |
0.50 |
| 2026-05-21 00:00 |
20:55:08.44 |
-17:54:57.6 |
HIP 103226 |
4.91 |
| 2026-05-21 12:00 |
20:55:26.89 |
-17:54:47.4 |
HIP 103226 |
9.30 |
| 2026-05-22 00:00 |
20:55:45.09 |
-17:54:38.6 |
HIP 103226 |
13.64 |
| 2026-05-22 12:00 |
20:56:03.05 |
-17:54:31.2 |
HIP 103226 |
17.91 |
| 2026-05-23 00:00 |
20:56:20.75 |
-17:54:25.2 |
HIP 103436 |
15.09 |
| 2026-05-23 12:00 |
20:56:38.19 |
-17:54:20.7 |
HIP 103436 |
11.10 |
| 2026-05-24 00:00 |
20:56:55.38 |
-17:54:17.6 |
HIP 103436 |
7.35 |
| 2026-05-24 12:00 |
20:57:12.31 |
-17:54:16.1 |
HIP 103436 |
4.33 |
| 2026-05-25 00:00 |
20:57:28.98 |
-17:54:16.0 |
HIP 103436 |
3.99 |
| 2026-05-25 12:00 |
20:57:45.39 |
-17:54:17.4 |
HIP 103436 |
6.64 |
| 2026-05-26 00:00 |
20:58:01.54 |
-17:54:20.3 |
HIP 103436 |
10.08 |
| 2026-05-26 12:00 |
20:58:17.42 |
-17:54:24.7 |
HIP 103436 |
13.69 |
| 2026-05-27 00:00 |
20:58:33.03 |
-17:54:30.7 |
HIP 103436 |
17.31 |
| 2026-05-27 12:00 |
20:58:48.38 |
-17:54:38.3 |
HIP 103436 |
20.91 |
| 2026-05-28 00:00 |
20:59:03.45 |
-17:54:47.5 |
HIP 103436 |
24.46 |
| 2026-05-28 12:00 |
20:59:18.25 |
-17:54:58.2 |
HIP 103618 |
27.41 |
| 2026-05-29 00:00 |
20:59:32.78 |
-17:55:10.6 |
HIP 103618 |
27.22 |
| 2026-05-29 12:00 |
20:59:47.03 |
-17:55:24.5 |
HIP 103618 |
27.49 |
| 2026-05-30 00:00 |
21:00:01.00 |
-17:55:40.2 |
HIP 103703 |
26.71 |
| 2026-05-30 12:00 |
21:00:14.69 |
-17:55:57.5 |
HIP 103703 |
25.67 |
| 2026-05-31 00:00 |
21:00:28.09 |
-17:56:16.4 |
HIP 103703 |
25.07 |
| 2026-05-31 12:00 |
21:00:41.21 |
-17:56:37.1 |
HIP 103703 |
24.89 |
| 2026-06-01 00:00 |
21:00:54.04 |
-17:56:59.4 |
HIP 103703 |
25.14 |
| 2026-06-01 12:00 |
21:01:06.59 |
-17:57:23.5 |
HIP 103703 |
25.78 |
| 2026-06-02 00:00 |
21:01:18.84 |
-17:57:49.3 |
HIP 103703 |
26.76 |