C/1899 S1 (Giacobini)
| 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) |
| 2026-02-03 00:00 |
06:13:02.66 |
+25:33:15.0 |
HIP 29454 |
9.38 |
| 2026-02-03 12:00 |
06:13:01.94 |
+25:33:14.8 |
HIP 29454 |
9.21 |
| 2026-02-04 00:00 |
06:13:01.22 |
+25:33:14.5 |
HIP 29454 |
9.06 |
| 2026-02-04 12:00 |
06:13:00.51 |
+25:33:14.2 |
HIP 29454 |
8.90 |
| 2026-02-05 00:00 |
06:12:59.80 |
+25:33:14.0 |
HIP 29454 |
8.74 |
| 2026-02-05 12:00 |
06:12:59.10 |
+25:33:13.7 |
HIP 29454 |
8.58 |
| 2026-02-06 00:00 |
06:12:58.41 |
+25:33:13.4 |
HIP 29454 |
8.43 |
| 2026-02-06 12:00 |
06:12:57.72 |
+25:33:13.1 |
HIP 29454 |
8.28 |
| 2026-02-07 00:00 |
06:12:57.03 |
+25:33:12.8 |
HIP 29454 |
8.13 |
| 2026-02-07 12:00 |
06:12:56.35 |
+25:33:12.5 |
HIP 29454 |
7.97 |
| 2026-02-08 00:00 |
06:12:55.68 |
+25:33:12.2 |
HIP 29454 |
7.83 |
| 2026-02-08 12:00 |
06:12:55.02 |
+25:33:11.9 |
HIP 29454 |
7.68 |
| 2026-02-09 00:00 |
06:12:54.36 |
+25:33:11.5 |
HIP 29454 |
7.53 |
| 2026-02-09 12:00 |
06:12:53.70 |
+25:33:11.2 |
HIP 29454 |
7.39 |
| 2026-02-10 00:00 |
06:12:53.06 |
+25:33:10.9 |
HIP 29454 |
7.24 |
| 2026-02-10 12:00 |
06:12:52.41 |
+25:33:10.6 |
HIP 29454 |
7.10 |
| 2026-02-11 00:00 |
06:12:51.78 |
+25:33:10.2 |
HIP 29454 |
6.96 |
| 2026-02-11 12:00 |
06:12:51.15 |
+25:33:09.9 |
HIP 29454 |
6.82 |
| 2026-02-12 00:00 |
06:12:50.53 |
+25:33:09.5 |
HIP 29454 |
6.69 |
| 2026-02-12 12:00 |
06:12:49.91 |
+25:33:09.2 |
HIP 29454 |
6.55 |
| 2026-02-13 00:00 |
06:12:49.30 |
+25:33:08.8 |
HIP 29454 |
6.42 |
| 2026-02-13 12:00 |
06:12:48.70 |
+25:33:08.5 |
HIP 29454 |
6.28 |
| 2026-02-14 00:00 |
06:12:48.11 |
+25:33:08.1 |
HIP 29454 |
6.15 |
| 2026-02-14 12:00 |
06:12:47.52 |
+25:33:07.7 |
HIP 29454 |
6.02 |
| 2026-02-15 00:00 |
06:12:46.93 |
+25:33:07.3 |
HIP 29454 |
5.90 |
| 2026-02-15 12:00 |
06:12:46.36 |
+25:33:07.0 |
HIP 29454 |
5.77 |
| 2026-02-16 00:00 |
06:12:45.79 |
+25:33:06.6 |
HIP 29454 |
5.65 |
| 2026-02-16 12:00 |
06:12:45.22 |
+25:33:06.2 |
HIP 29454 |
5.52 |
| 2026-02-17 00:00 |
06:12:44.67 |
+25:33:05.8 |
HIP 29454 |
5.40 |
| 2026-02-17 12:00 |
06:12:44.12 |
+25:33:05.4 |
HIP 29454 |
5.28 |
| 2026-02-18 00:00 |
06:12:43.58 |
+25:33:05.0 |
HIP 29454 |
5.16 |
| 2026-02-18 12:00 |
06:12:43.04 |
+25:33:04.6 |
HIP 29454 |
5.05 |
| 2026-02-19 00:00 |
06:12:42.52 |
+25:33:04.2 |
HIP 29454 |
4.93 |
| 2026-02-19 12:00 |
06:12:41.99 |
+25:33:03.8 |
HIP 29454 |
4.82 |
| 2026-02-20 00:00 |
06:12:41.48 |
+25:33:03.3 |
HIP 29454 |
4.71 |
| 2026-02-20 12:00 |
06:12:40.97 |
+25:33:02.9 |
HIP 29454 |
4.60 |
| 2026-02-21 00:00 |
06:12:40.47 |
+25:33:02.5 |
HIP 29454 |
4.49 |
| 2026-02-21 12:00 |
06:12:39.98 |
+25:33:02.0 |
HIP 29454 |
4.38 |
| 2026-02-22 00:00 |
06:12:39.50 |
+25:33:01.6 |
HIP 29454 |
4.28 |
| 2026-02-22 12:00 |
06:12:39.02 |
+25:33:01.2 |
HIP 29454 |
4.18 |
| 2026-02-23 00:00 |
06:12:38.55 |
+25:33:00.7 |
HIP 29454 |
4.08 |
| 2026-02-23 12:00 |
06:12:38.09 |
+25:33:00.3 |
HIP 29454 |
3.98 |
| 2026-02-24 00:00 |
06:12:37.63 |
+25:32:59.8 |
HIP 29454 |
3.88 |