| 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) |
| 2026-03-26 00:00 |
13:26:36.22 |
-10:59:58.9 |
HIP 65474 |
22.91 |
| 2026-03-26 12:00 |
13:26:35.47 |
-10:59:54.7 |
HIP 65474 |
22.77 |
| 2026-03-27 00:00 |
13:26:34.72 |
-10:59:50.5 |
HIP 65474 |
22.64 |
| 2026-03-27 12:00 |
13:26:33.97 |
-10:59:46.3 |
HIP 65474 |
22.50 |
| 2026-03-28 00:00 |
13:26:33.22 |
-10:59:42.1 |
HIP 65474 |
22.37 |
| 2026-03-28 12:00 |
13:26:32.47 |
-10:59:37.8 |
HIP 65474 |
22.24 |
| 2026-03-29 00:00 |
13:26:31.71 |
-10:59:33.5 |
HIP 65474 |
22.10 |
| 2026-03-29 12:00 |
13:26:30.96 |
-10:59:29.3 |
HIP 65474 |
21.97 |
| 2026-03-30 00:00 |
13:26:30.20 |
-10:59:25.0 |
HIP 65474 |
21.84 |
| 2026-03-30 12:00 |
13:26:29.44 |
-10:59:20.7 |
HIP 65474 |
21.71 |
| 2026-03-31 00:00 |
13:26:28.67 |
-10:59:16.3 |
HIP 65474 |
21.58 |
| 2026-03-31 12:00 |
13:26:27.91 |
-10:59:12.0 |
HIP 65474 |
21.45 |
| 2026-04-01 00:00 |
13:26:27.14 |
-10:59:07.7 |
HIP 65474 |
21.32 |
| 2026-04-01 12:00 |
13:26:26.38 |
-10:59:03.3 |
HIP 65474 |
21.20 |
| 2026-04-02 00:00 |
13:26:25.61 |
-10:58:59.0 |
HIP 65474 |
21.07 |
| 2026-04-02 12:00 |
13:26:24.84 |
-10:58:54.6 |
HIP 65474 |
20.95 |
| 2026-04-03 00:00 |
13:26:24.07 |
-10:58:50.2 |
HIP 65474 |
20.82 |
| 2026-04-03 12:00 |
13:26:23.30 |
-10:58:45.8 |
HIP 65474 |
20.70 |
| 2026-04-04 00:00 |
13:26:22.52 |
-10:58:41.4 |
HIP 65474 |
20.58 |
| 2026-04-04 12:00 |
13:26:21.75 |
-10:58:36.9 |
HIP 65474 |
20.46 |
| 2026-04-05 00:00 |
13:26:20.97 |
-10:58:32.5 |
HIP 65474 |
20.34 |
| 2026-04-05 12:00 |
13:26:20.20 |
-10:58:28.1 |
HIP 65474 |
20.22 |
| 2026-04-06 00:00 |
13:26:19.42 |
-10:58:23.6 |
HIP 65474 |
20.10 |
| 2026-04-06 12:00 |
13:26:18.64 |
-10:58:19.2 |
HIP 65474 |
19.99 |
| 2026-04-07 00:00 |
13:26:17.86 |
-10:58:14.7 |
HIP 65474 |
19.87 |
| 2026-04-07 12:00 |
13:26:17.08 |
-10:58:10.2 |
HIP 65474 |
19.76 |
| 2026-04-08 00:00 |
13:26:16.30 |
-10:58:05.7 |
HIP 65474 |
19.65 |
| 2026-04-08 12:00 |
13:26:15.52 |
-10:58:01.2 |
HIP 65474 |
19.54 |
| 2026-04-09 00:00 |
13:26:14.74 |
-10:57:56.7 |
HIP 65474 |
19.43 |
| 2026-04-09 12:00 |
13:26:13.95 |
-10:57:52.2 |
HIP 65474 |
19.32 |
| 2026-04-10 00:00 |
13:26:13.17 |
-10:57:47.7 |
HIP 65474 |
19.22 |
| 2026-04-10 12:00 |
13:26:12.39 |
-10:57:43.2 |
HIP 65474 |
19.11 |
| 2026-04-11 00:00 |
13:26:11.60 |
-10:57:38.7 |
HIP 65474 |
19.01 |
| 2026-04-11 12:00 |
13:26:10.82 |
-10:57:34.1 |
HIP 65474 |
18.91 |
| 2026-04-12 00:00 |
13:26:10.04 |
-10:57:29.6 |
HIP 65474 |
18.81 |
| 2026-04-12 12:00 |
13:26:09.25 |
-10:57:25.1 |
HIP 65474 |
18.72 |
| 2026-04-13 00:00 |
13:26:08.47 |
-10:57:20.5 |
HIP 65474 |
18.62 |
| 2026-04-13 12:00 |
13:26:07.68 |
-10:57:16.0 |
HIP 65474 |
18.53 |
| 2026-04-14 00:00 |
13:26:06.90 |
-10:57:11.4 |
HIP 65474 |
18.44 |
| 2026-04-14 12:00 |
13:26:06.11 |
-10:57:06.9 |
HIP 65474 |
18.35 |
| 2026-04-15 00:00 |
13:26:05.33 |
-10:57:02.3 |
HIP 65474 |
18.26 |
| 2026-04-15 12:00 |
13:26:04.54 |
-10:56:57.7 |
HIP 65474 |
18.17 |
| 2026-04-16 00:00 |
13:26:03.76 |
-10:56:53.2 |
HIP 65474 |
18.09 |