| Parameter |
Value |
| Designation |
C/1879 M1 (Swift) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1879-04-27T22:12:15.344640Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:28:51Z |
| Obs used |
16 |
| NEO |
- |
| M1 |
6.100 |
| K1 |
17.750 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1879-07-15.0000000 |
| e |
1.00000000 |
| q (au) |
0.896364 |
| a (au) |
- |
| i (deg) |
107.044636 |
| Ω (om, deg) |
47.452641 |
| ω (w, deg) |
3.742746 |
| 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) |
| 2026-05-12 00:00 |
15:11:23.58 |
-12:52:35.5 |
HIP 74301 |
10.94 |
| 2026-05-12 12:00 |
15:11:22.83 |
-12:52:32.6 |
HIP 74301 |
10.95 |
| 2026-05-13 00:00 |
15:11:22.08 |
-12:52:29.6 |
HIP 74301 |
10.96 |
| 2026-05-13 12:00 |
15:11:21.33 |
-12:52:26.7 |
HIP 74301 |
10.98 |
| 2026-05-14 00:00 |
15:11:20.58 |
-12:52:23.8 |
HIP 74301 |
11.00 |
| 2026-05-14 12:00 |
15:11:19.83 |
-12:52:20.9 |
HIP 74301 |
11.02 |
| 2026-05-15 00:00 |
15:11:19.08 |
-12:52:18.0 |
HIP 74301 |
11.04 |
| 2026-05-15 12:00 |
15:11:18.33 |
-12:52:15.2 |
HIP 74301 |
11.07 |
| 2026-05-16 00:00 |
15:11:17.58 |
-12:52:12.3 |
HIP 74301 |
11.10 |
| 2026-05-16 12:00 |
15:11:16.83 |
-12:52:09.5 |
HIP 74301 |
11.13 |
| 2026-05-17 00:00 |
15:11:16.08 |
-12:52:06.6 |
HIP 74301 |
11.17 |
| 2026-05-17 12:00 |
15:11:15.33 |
-12:52:03.8 |
HIP 74301 |
11.20 |
| 2026-05-18 00:00 |
15:11:14.59 |
-12:52:01.0 |
HIP 74301 |
11.25 |
| 2026-05-18 12:00 |
15:11:13.84 |
-12:51:58.1 |
HIP 74301 |
11.29 |
| 2026-05-19 00:00 |
15:11:13.10 |
-12:51:55.3 |
HIP 74301 |
11.34 |
| 2026-05-19 12:00 |
15:11:12.35 |
-12:51:52.6 |
HIP 74301 |
11.39 |
| 2026-05-20 00:00 |
15:11:11.61 |
-12:51:49.8 |
HIP 74301 |
11.44 |
| 2026-05-20 12:00 |
15:11:10.87 |
-12:51:47.0 |
HIP 74301 |
11.49 |
| 2026-05-21 00:00 |
15:11:10.13 |
-12:51:44.3 |
HIP 74301 |
11.55 |
| 2026-05-21 12:00 |
15:11:09.39 |
-12:51:41.5 |
HIP 74301 |
11.61 |
| 2026-05-22 00:00 |
15:11:08.65 |
-12:51:38.8 |
HIP 74301 |
11.67 |
| 2026-05-22 12:00 |
15:11:07.91 |
-12:51:36.1 |
HIP 74301 |
11.74 |
| 2026-05-23 00:00 |
15:11:07.17 |
-12:51:33.4 |
HIP 74301 |
11.80 |
| 2026-05-23 12:00 |
15:11:06.44 |
-12:51:30.7 |
HIP 74301 |
11.87 |
| 2026-05-24 00:00 |
15:11:05.70 |
-12:51:28.0 |
HIP 74301 |
11.94 |
| 2026-05-24 12:00 |
15:11:04.97 |
-12:51:25.4 |
HIP 74301 |
12.02 |
| 2026-05-25 00:00 |
15:11:04.24 |
-12:51:22.7 |
HIP 74301 |
12.09 |
| 2026-05-25 12:00 |
15:11:03.51 |
-12:51:20.1 |
HIP 74301 |
12.17 |
| 2026-05-26 00:00 |
15:11:02.78 |
-12:51:17.5 |
HIP 74301 |
12.25 |
| 2026-05-26 12:00 |
15:11:02.06 |
-12:51:14.9 |
HIP 74301 |
12.33 |
| 2026-05-27 00:00 |
15:11:01.33 |
-12:51:12.3 |
HIP 74301 |
12.41 |
| 2026-05-27 12:00 |
15:11:00.61 |
-12:51:09.7 |
HIP 74301 |
12.50 |
| 2026-05-28 00:00 |
15:10:59.89 |
-12:51:07.1 |
HIP 74301 |
12.59 |
| 2026-05-28 12:00 |
15:10:59.17 |
-12:51:04.6 |
HIP 74301 |
12.67 |
| 2026-05-29 00:00 |
15:10:58.45 |
-12:51:02.1 |
HIP 74301 |
12.76 |
| 2026-05-29 12:00 |
15:10:57.74 |
-12:50:59.6 |
HIP 74301 |
12.85 |
| 2026-05-30 00:00 |
15:10:57.02 |
-12:50:57.1 |
HIP 74301 |
12.95 |
| 2026-05-30 12:00 |
15:10:56.31 |
-12:50:54.6 |
HIP 74301 |
13.04 |
| 2026-05-31 00:00 |
15:10:55.60 |
-12:50:52.1 |
HIP 74301 |
13.14 |
| 2026-05-31 12:00 |
15:10:54.90 |
-12:50:49.7 |
HIP 74301 |
13.23 |
| 2026-06-01 00:00 |
15:10:54.19 |
-12:50:47.2 |
HIP 74301 |
13.33 |
| 2026-06-01 12:00 |
15:10:53.49 |
-12:50:44.8 |
HIP 74301 |
13.43 |
| 2026-06-02 00:00 |
15:10:52.79 |
-12:50:42.4 |
HIP 74301 |
13.53 |