| Parameter |
Value |
| Designation |
C/1915 C1 (Mellish) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1915-07-17T15:36:50.613120Z |
| Orbit solution date (soln_date, UTC) |
2024-04-15T15:43:28Z |
| Obs used |
94 |
| NEO |
- |
| M1 |
7.700 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1915-06-30.0000000 |
| e |
1.00027442 |
| q (au) |
1.005324 |
| a (au) |
-3663.395604 |
| i (deg) |
54.791644 |
| Ω (om, deg) |
73.453125 |
| ω (w, deg) |
247.782134 |
| M (ma, deg) |
-0.000078 |
Magnitude
Scatter + Global Linear
$$
M_a = (9.514 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
9.514 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.852 |
| k |
0.800 |
| δ90 |
10.000 |
| 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 |
09:00:13.15 |
+62:57:55.8 |
HIP 44397 |
23.39 |
| 2026-09-20 12:00 |
09:00:14.54 |
+62:58:01.0 |
HIP 44397 |
23.21 |
| 2026-09-21 00:00 |
09:00:15.92 |
+62:58:06.2 |
HIP 44397 |
23.04 |
| 2026-09-21 12:00 |
09:00:17.29 |
+62:58:11.6 |
HIP 44397 |
22.87 |
| 2026-09-22 00:00 |
09:00:18.64 |
+62:58:17.0 |
HIP 44397 |
22.70 |
| 2026-09-22 12:00 |
09:00:19.99 |
+62:58:22.5 |
HIP 44397 |
22.53 |
| 2026-09-23 00:00 |
09:00:21.32 |
+62:58:28.1 |
HIP 44397 |
22.36 |
| 2026-09-23 12:00 |
09:00:22.64 |
+62:58:33.8 |
HIP 44397 |
22.19 |
| 2026-09-24 00:00 |
09:00:23.95 |
+62:58:39.5 |
HIP 44397 |
22.02 |
| 2026-09-24 12:00 |
09:00:25.25 |
+62:58:45.3 |
HIP 44397 |
21.84 |
| 2026-09-25 00:00 |
09:00:26.53 |
+62:58:51.2 |
HIP 44397 |
21.67 |
| 2026-09-25 12:00 |
09:00:27.80 |
+62:58:57.1 |
HIP 44397 |
21.50 |
| 2026-09-26 00:00 |
09:00:29.06 |
+62:59:03.1 |
HIP 44397 |
21.33 |
| 2026-09-26 12:00 |
09:00:30.31 |
+62:59:09.2 |
HIP 44397 |
21.16 |
| 2026-09-27 00:00 |
09:00:31.54 |
+62:59:15.4 |
HIP 44397 |
20.99 |
| 2026-09-27 12:00 |
09:00:32.76 |
+62:59:21.6 |
HIP 44397 |
20.82 |
| 2026-09-28 00:00 |
09:00:33.97 |
+62:59:27.9 |
HIP 44397 |
20.65 |
| 2026-09-28 12:00 |
09:00:35.17 |
+62:59:34.3 |
HIP 44397 |
20.48 |
| 2026-09-29 00:00 |
09:00:36.35 |
+62:59:40.8 |
HIP 44397 |
20.31 |
| 2026-09-29 12:00 |
09:00:37.52 |
+62:59:47.3 |
HIP 44397 |
20.14 |
| 2026-09-30 00:00 |
09:00:38.68 |
+62:59:53.9 |
HIP 44397 |
19.97 |
| 2026-09-30 12:00 |
09:00:39.82 |
+63:00:00.5 |
HIP 44397 |
19.80 |
| 2026-10-01 00:00 |
09:00:40.95 |
+63:00:07.2 |
HIP 44397 |
19.64 |
| 2026-10-01 12:00 |
09:00:42.07 |
+63:00:14.0 |
HIP 44397 |
19.47 |
| 2026-10-02 00:00 |
09:00:43.17 |
+63:00:20.9 |
HIP 44397 |
19.30 |
| 2026-10-02 12:00 |
09:00:44.26 |
+63:00:27.8 |
HIP 44397 |
19.13 |
| 2026-10-03 00:00 |
09:00:45.34 |
+63:00:34.8 |
HIP 44397 |
18.96 |
| 2026-10-03 12:00 |
09:00:46.40 |
+63:00:41.9 |
HIP 44397 |
18.79 |
| 2026-10-04 00:00 |
09:00:47.45 |
+63:00:49.0 |
HIP 44397 |
18.63 |
| 2026-10-04 12:00 |
09:00:48.48 |
+63:00:56.2 |
HIP 44397 |
18.46 |
| 2026-10-05 00:00 |
09:00:49.50 |
+63:01:03.5 |
HIP 44397 |
18.29 |
| 2026-10-05 12:00 |
09:00:50.51 |
+63:01:10.8 |
HIP 44397 |
18.12 |
| 2026-10-06 00:00 |
09:00:51.50 |
+63:01:18.2 |
HIP 44397 |
17.96 |
| 2026-10-06 12:00 |
09:00:52.48 |
+63:01:25.6 |
HIP 44397 |
17.79 |
| 2026-10-07 00:00 |
09:00:53.44 |
+63:01:33.2 |
HIP 44397 |
17.62 |
| 2026-10-07 12:00 |
09:00:54.39 |
+63:01:40.8 |
HIP 44397 |
17.46 |
| 2026-10-08 00:00 |
09:00:55.32 |
+63:01:48.4 |
HIP 44397 |
17.29 |
| 2026-10-08 12:00 |
09:00:56.24 |
+63:01:56.1 |
HIP 44397 |
17.13 |
| 2026-10-09 00:00 |
09:00:57.15 |
+63:02:03.9 |
HIP 44397 |
16.96 |
| 2026-10-09 12:00 |
09:00:58.04 |
+63:02:11.7 |
HIP 44397 |
16.80 |
| 2026-10-10 00:00 |
09:00:58.91 |
+63:02:19.6 |
HIP 44397 |
16.63 |
| 2026-10-10 12:00 |
09:00:59.77 |
+63:02:27.6 |
HIP 44397 |
16.47 |
| 2026-10-11 00:00 |
09:01:00.62 |
+63:02:35.6 |
HIP 44397 |
16.31 |