| Parameter |
Value |
| Designation |
C/1899 E1 (Swift) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1899-04-13T11:27:00.100800Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:28:55Z |
| Obs used |
151 |
| NEO |
- |
| M1 |
- |
| K1 |
- |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1899-05-04.0000000 |
| e |
1.00032525 |
| q (au) |
0.326562 |
| a (au) |
-1004.044294 |
| i (deg) |
146.270427 |
| Ω (om, deg) |
26.405893 |
| ω (w, deg) |
8.705696 |
| M (ma, deg) |
0.000636 |
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) |
| 2026-09-20 00:00 |
13:25:25.91 |
-10:51:53.6 |
HIP 65474 |
18.12 |
| 2026-09-20 12:00 |
13:25:26.59 |
-10:51:57.5 |
HIP 65474 |
18.09 |
| 2026-09-21 00:00 |
13:25:27.29 |
-10:52:01.5 |
HIP 65474 |
18.06 |
| 2026-09-21 12:00 |
13:25:27.98 |
-10:52:05.4 |
HIP 65474 |
18.04 |
| 2026-09-22 00:00 |
13:25:28.68 |
-10:52:09.4 |
HIP 65474 |
18.01 |
| 2026-09-22 12:00 |
13:25:29.38 |
-10:52:13.4 |
HIP 65474 |
17.99 |
| 2026-09-23 00:00 |
13:25:30.08 |
-10:52:17.4 |
HIP 65474 |
17.97 |
| 2026-09-23 12:00 |
13:25:30.79 |
-10:52:21.4 |
HIP 65474 |
17.95 |
| 2026-09-24 00:00 |
13:25:31.49 |
-10:52:25.5 |
HIP 65474 |
17.93 |
| 2026-09-24 12:00 |
13:25:32.20 |
-10:52:29.5 |
HIP 65474 |
17.91 |
| 2026-09-25 00:00 |
13:25:32.92 |
-10:52:33.6 |
HIP 65474 |
17.90 |
| 2026-09-25 12:00 |
13:25:33.63 |
-10:52:37.7 |
HIP 65474 |
17.88 |
| 2026-09-26 00:00 |
13:25:34.35 |
-10:52:41.8 |
HIP 65474 |
17.87 |
| 2026-09-26 12:00 |
13:25:35.07 |
-10:52:46.0 |
HIP 65474 |
17.86 |
| 2026-09-27 00:00 |
13:25:35.79 |
-10:52:50.1 |
HIP 65474 |
17.85 |
| 2026-09-27 12:00 |
13:25:36.51 |
-10:52:54.3 |
HIP 65474 |
17.85 |
| 2026-09-28 00:00 |
13:25:37.24 |
-10:52:58.4 |
HIP 65474 |
17.85 |
| 2026-09-28 12:00 |
13:25:37.97 |
-10:53:02.6 |
HIP 65474 |
17.84 |
| 2026-09-29 00:00 |
13:25:38.70 |
-10:53:06.8 |
HIP 65474 |
17.85 |
| 2026-09-29 12:00 |
13:25:39.43 |
-10:53:11.1 |
HIP 65474 |
17.85 |
| 2026-09-30 00:00 |
13:25:40.16 |
-10:53:15.3 |
HIP 65474 |
17.85 |
| 2026-09-30 12:00 |
13:25:40.90 |
-10:53:19.5 |
HIP 65474 |
17.86 |
| 2026-10-01 00:00 |
13:25:41.64 |
-10:53:23.8 |
HIP 65474 |
17.87 |
| 2026-10-01 12:00 |
13:25:42.38 |
-10:53:28.1 |
HIP 65474 |
17.88 |
| 2026-10-02 00:00 |
13:25:43.12 |
-10:53:32.4 |
HIP 65474 |
17.89 |
| 2026-10-02 12:00 |
13:25:43.86 |
-10:53:36.7 |
HIP 65474 |
17.91 |
| 2026-10-03 00:00 |
13:25:44.60 |
-10:53:41.0 |
HIP 65474 |
17.92 |
| 2026-10-03 12:00 |
13:25:45.35 |
-10:53:45.3 |
HIP 65474 |
17.94 |
| 2026-10-04 00:00 |
13:25:46.10 |
-10:53:49.7 |
HIP 65474 |
17.97 |
| 2026-10-04 12:00 |
13:25:46.85 |
-10:53:54.0 |
HIP 65474 |
17.99 |
| 2026-10-05 00:00 |
13:25:47.60 |
-10:53:58.4 |
HIP 65474 |
18.01 |
| 2026-10-05 12:00 |
13:25:48.35 |
-10:54:02.8 |
HIP 65474 |
18.04 |
| 2026-10-06 00:00 |
13:25:49.10 |
-10:54:07.2 |
HIP 65474 |
18.07 |
| 2026-10-06 12:00 |
13:25:49.86 |
-10:54:11.6 |
HIP 65474 |
18.11 |
| 2026-10-07 00:00 |
13:25:50.61 |
-10:54:16.0 |
HIP 65474 |
18.14 |
| 2026-10-07 12:00 |
13:25:51.37 |
-10:54:20.4 |
HIP 65474 |
18.18 |
| 2026-10-08 00:00 |
13:25:52.13 |
-10:54:24.8 |
HIP 65474 |
18.21 |
| 2026-10-08 12:00 |
13:25:52.89 |
-10:54:29.3 |
HIP 65474 |
18.26 |
| 2026-10-09 00:00 |
13:25:53.65 |
-10:54:33.7 |
HIP 65474 |
18.30 |
| 2026-10-09 12:00 |
13:25:54.41 |
-10:54:38.2 |
HIP 65474 |
18.34 |
| 2026-10-10 00:00 |
13:25:55.17 |
-10:54:42.6 |
HIP 65474 |
18.39 |
| 2026-10-10 12:00 |
13:25:55.93 |
-10:54:47.1 |
HIP 65474 |
18.44 |
| 2026-10-11 00:00 |
13:25:56.69 |
-10:54:51.6 |
HIP 65474 |
18.49 |