| Parameter |
Value |
| Designation |
C/1972 F1 (Gehrels) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1971-01-06T12:19:44.146560Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:19Z |
| Obs used |
18 |
| NEO |
- |
| M1 |
- |
| K1 |
- |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1972-08-05.0000000 |
| e |
0.99788599 |
| q (au) |
3.276471 |
| a (au) |
1549.882081 |
| i (deg) |
175.610745 |
| Ω (om, deg) |
24.754752 |
| ω (w, deg) |
128.702717 |
| M (ma, deg) |
0.009312 |
Magnitude
Scatter + Global Linear
$$
M_a = (8.957 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
8.957 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.900 |
| 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) |
| 2026-03-26 00:00 |
06:36:31.22 |
+18:55:58.4 |
HIP 31618 |
15.46 |
| 2026-03-26 12:00 |
06:36:31.06 |
+18:56:00.2 |
HIP 31618 |
15.45 |
| 2026-03-27 00:00 |
06:36:30.91 |
+18:56:02.0 |
HIP 31618 |
15.44 |
| 2026-03-27 12:00 |
06:36:30.78 |
+18:56:03.9 |
HIP 31618 |
15.43 |
| 2026-03-28 00:00 |
06:36:30.66 |
+18:56:05.7 |
HIP 31618 |
15.42 |
| 2026-03-28 12:00 |
06:36:30.55 |
+18:56:07.5 |
HIP 31618 |
15.40 |
| 2026-03-29 00:00 |
06:36:30.45 |
+18:56:09.3 |
HIP 31618 |
15.39 |
| 2026-03-29 12:00 |
06:36:30.37 |
+18:56:11.0 |
HIP 31618 |
15.37 |
| 2026-03-30 00:00 |
06:36:30.31 |
+18:56:12.8 |
HIP 31618 |
15.35 |
| 2026-03-30 12:00 |
06:36:30.25 |
+18:56:14.5 |
HIP 31618 |
15.33 |
| 2026-03-31 00:00 |
06:36:30.22 |
+18:56:16.3 |
HIP 31618 |
15.31 |
| 2026-03-31 12:00 |
06:36:30.19 |
+18:56:18.0 |
HIP 31618 |
15.29 |
| 2026-04-01 00:00 |
06:36:30.18 |
+18:56:19.7 |
HIP 31618 |
15.27 |
| 2026-04-01 12:00 |
06:36:30.18 |
+18:56:21.4 |
HIP 31618 |
15.24 |
| 2026-04-02 00:00 |
06:36:30.20 |
+18:56:23.1 |
HIP 31618 |
15.22 |
| 2026-04-02 12:00 |
06:36:30.23 |
+18:56:24.7 |
HIP 31618 |
15.19 |
| 2026-04-03 00:00 |
06:36:30.27 |
+18:56:26.4 |
HIP 31618 |
15.16 |
| 2026-04-03 12:00 |
06:36:30.33 |
+18:56:28.0 |
HIP 31618 |
15.13 |
| 2026-04-04 00:00 |
06:36:30.40 |
+18:56:29.7 |
HIP 31618 |
15.10 |
| 2026-04-04 12:00 |
06:36:30.48 |
+18:56:31.3 |
HIP 31618 |
15.06 |
| 2026-04-05 00:00 |
06:36:30.58 |
+18:56:32.9 |
HIP 31618 |
15.03 |
| 2026-04-05 12:00 |
06:36:30.69 |
+18:56:34.4 |
HIP 31618 |
14.99 |
| 2026-04-06 00:00 |
06:36:30.82 |
+18:56:36.0 |
HIP 31618 |
14.96 |
| 2026-04-06 12:00 |
06:36:30.96 |
+18:56:37.6 |
HIP 31618 |
14.92 |
| 2026-04-07 00:00 |
06:36:31.11 |
+18:56:39.1 |
HIP 31618 |
14.88 |
| 2026-04-07 12:00 |
06:36:31.27 |
+18:56:40.6 |
HIP 31618 |
14.84 |
| 2026-04-08 00:00 |
06:36:31.45 |
+18:56:42.2 |
HIP 31618 |
14.79 |
| 2026-04-08 12:00 |
06:36:31.65 |
+18:56:43.7 |
HIP 31618 |
14.75 |
| 2026-04-09 00:00 |
06:36:31.85 |
+18:56:45.1 |
HIP 31618 |
14.70 |
| 2026-04-09 12:00 |
06:36:32.07 |
+18:56:46.6 |
HIP 31618 |
14.66 |
| 2026-04-10 00:00 |
06:36:32.30 |
+18:56:48.1 |
HIP 31618 |
14.61 |
| 2026-04-10 12:00 |
06:36:32.55 |
+18:56:49.5 |
HIP 31618 |
14.56 |
| 2026-04-11 00:00 |
06:36:32.81 |
+18:56:50.9 |
HIP 31618 |
14.51 |
| 2026-04-11 12:00 |
06:36:33.08 |
+18:56:52.3 |
HIP 31618 |
14.46 |
| 2026-04-12 00:00 |
06:36:33.37 |
+18:56:53.7 |
HIP 31618 |
14.41 |
| 2026-04-12 12:00 |
06:36:33.67 |
+18:56:55.1 |
HIP 31618 |
14.35 |
| 2026-04-13 00:00 |
06:36:33.98 |
+18:56:56.4 |
HIP 31618 |
14.30 |
| 2026-04-13 12:00 |
06:36:34.31 |
+18:56:57.8 |
HIP 31618 |
14.24 |
| 2026-04-14 00:00 |
06:36:34.65 |
+18:56:59.1 |
HIP 31618 |
14.19 |
| 2026-04-14 12:00 |
06:36:35.00 |
+18:57:00.4 |
HIP 31618 |
14.13 |
| 2026-04-15 00:00 |
06:36:35.37 |
+18:57:01.7 |
HIP 31618 |
14.07 |
| 2026-04-15 12:00 |
06:36:35.75 |
+18:57:03.0 |
HIP 31618 |
14.01 |
| 2026-04-16 00:00 |
06:36:36.14 |
+18:57:04.3 |
HIP 31618 |
13.95 |