| Parameter |
Value |
| Designation |
C/1899 S1 (Giacobini) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1899-09-15T08:49:19.871040Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:28:57Z |
| Obs used |
36 |
| NEO |
- |
| M1 |
- |
| K1 |
- |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1899-10-29.0000000 |
| e |
1.00000000 |
| q (au) |
1.785616 |
| a (au) |
- |
| i (deg) |
76.948955 |
| Ω (om, deg) |
273.627412 |
| ω (w, deg) |
10.751760 |
| M (ma, deg) |
- |
Magnitude
Scatter + Global Linear
$$
M_a = (H_0 + n\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
- |
| n |
- |
| gf |
- |
| gb |
- |
| k |
- |
| δ90 |
- |
| 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) |
| 2026-06-01 00:00 |
06:13:30.63 |
+25:30:54.5 |
HIP 29454 |
15.52 |
| 2026-06-01 12:00 |
06:13:31.47 |
+25:30:53.9 |
HIP 29454 |
15.71 |
| 2026-06-02 00:00 |
06:13:32.32 |
+25:30:53.3 |
HIP 29454 |
15.90 |
| 2026-06-02 12:00 |
06:13:33.17 |
+25:30:52.7 |
HIP 29454 |
16.09 |
| 2026-06-03 00:00 |
06:13:34.03 |
+25:30:52.1 |
HIP 29454 |
16.29 |
| 2026-06-03 12:00 |
06:13:34.89 |
+25:30:51.5 |
HIP 29454 |
16.48 |
| 2026-06-04 00:00 |
06:13:35.75 |
+25:30:50.9 |
HIP 29454 |
16.67 |
| 2026-06-04 12:00 |
06:13:36.61 |
+25:30:50.3 |
HIP 29454 |
16.87 |
| 2026-06-05 00:00 |
06:13:37.48 |
+25:30:49.7 |
HIP 29454 |
17.06 |
| 2026-06-05 12:00 |
06:13:38.34 |
+25:30:49.1 |
HIP 29454 |
17.26 |
| 2026-06-06 00:00 |
06:13:39.22 |
+25:30:48.5 |
HIP 29454 |
17.46 |
| 2026-06-06 12:00 |
06:13:40.09 |
+25:30:47.9 |
HIP 29454 |
17.65 |
| 2026-06-07 00:00 |
06:13:40.96 |
+25:30:47.3 |
HIP 29454 |
17.85 |
| 2026-06-07 12:00 |
06:13:41.84 |
+25:30:46.7 |
HIP 29454 |
18.05 |
| 2026-06-08 00:00 |
06:13:42.72 |
+25:30:46.2 |
HIP 29454 |
18.25 |
| 2026-06-08 12:00 |
06:13:43.60 |
+25:30:45.6 |
HIP 29454 |
18.45 |
| 2026-06-09 00:00 |
06:13:44.49 |
+25:30:45.0 |
HIP 29454 |
18.65 |
| 2026-06-09 12:00 |
06:13:45.37 |
+25:30:44.4 |
HIP 29454 |
18.85 |
| 2026-06-10 00:00 |
06:13:46.26 |
+25:30:43.9 |
HIP 29680 |
18.85 |
| 2026-06-10 12:00 |
06:13:47.15 |
+25:30:43.3 |
HIP 29680 |
18.65 |
| 2026-06-11 00:00 |
06:13:48.05 |
+25:30:42.7 |
HIP 29680 |
18.45 |
| 2026-06-11 12:00 |
06:13:48.94 |
+25:30:42.2 |
HIP 29680 |
18.25 |
| 2026-06-12 00:00 |
06:13:49.84 |
+25:30:41.6 |
HIP 29680 |
18.05 |
| 2026-06-12 12:00 |
06:13:50.73 |
+25:30:41.1 |
HIP 29680 |
17.85 |
| 2026-06-13 00:00 |
06:13:51.63 |
+25:30:40.5 |
HIP 29680 |
17.65 |
| 2026-06-13 12:00 |
06:13:52.53 |
+25:30:40.0 |
HIP 29680 |
17.45 |
| 2026-06-14 00:00 |
06:13:53.43 |
+25:30:39.4 |
HIP 29680 |
17.24 |
| 2026-06-14 12:00 |
06:13:54.34 |
+25:30:38.9 |
HIP 29680 |
17.04 |
| 2026-06-15 00:00 |
06:13:55.24 |
+25:30:38.3 |
HIP 29680 |
16.84 |
| 2026-06-15 12:00 |
06:13:56.15 |
+25:30:37.8 |
HIP 29680 |
16.64 |
| 2026-06-16 00:00 |
06:13:57.06 |
+25:30:37.2 |
HIP 29680 |
16.43 |
| 2026-06-16 12:00 |
06:13:57.96 |
+25:30:36.7 |
HIP 29680 |
16.23 |
| 2026-06-17 00:00 |
06:13:58.87 |
+25:30:36.2 |
HIP 29680 |
16.02 |
| 2026-06-17 12:00 |
06:13:59.78 |
+25:30:35.7 |
HIP 29680 |
15.82 |
| 2026-06-18 00:00 |
06:14:00.70 |
+25:30:35.1 |
HIP 29680 |
15.62 |
| 2026-06-18 12:00 |
06:14:01.61 |
+25:30:34.6 |
HIP 29680 |
15.41 |
| 2026-06-19 00:00 |
06:14:02.52 |
+25:30:34.1 |
HIP 29680 |
15.21 |
| 2026-06-19 12:00 |
06:14:03.43 |
+25:30:33.6 |
HIP 29680 |
15.00 |
| 2026-06-20 00:00 |
06:14:04.35 |
+25:30:33.1 |
HIP 29680 |
14.80 |
| 2026-06-20 12:00 |
06:14:05.26 |
+25:30:32.6 |
HIP 29680 |
14.59 |
| 2026-06-21 00:00 |
06:14:06.18 |
+25:30:32.1 |
HIP 29680 |
14.39 |
| 2026-06-21 12:00 |
06:14:07.09 |
+25:30:31.6 |
HIP 29680 |
14.18 |
| 2026-06-22 00:00 |
06:14:08.01 |
+25:30:31.1 |
HIP 29680 |
13.98 |