| Parameter |
Value |
| Designation |
C/1970 N1 (Abe) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1970-10-20T16:46:43.086720Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:19Z |
| Obs used |
271 |
| NEO |
- |
| M1 |
6.600 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1970-10-11.0000000 |
| e |
1.00003692 |
| q (au) |
1.112541 |
| a (au) |
-30136.217151 |
| i (deg) |
126.719910 |
| Ω (om, deg) |
21.701358 |
| ω (w, deg) |
96.583364 |
| M (ma, deg) |
-0.000002 |
Magnitude
Scatter + Global Linear
$$
M_a = (5.447 + 3.246\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
5.447 |
| n |
3.246 |
| gf |
0.800 |
| gb |
-0.948 |
| k |
0.999 |
| δ90 |
1.000 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 1970-07-05 |
1970-10-20 |
+1.2370 |
-0.055 |
| 1970-10-20 |
1971-03-07 |
-0.0609 |
-0.277 |
| 1971-03-07 |
1971-05-25 |
+5.0362 |
-1.623 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
07:34:46.59 |
-31:42:05.8 |
HIP 36897 |
12.92 |
| 2026-09-20 12:00 |
07:34:47.24 |
-31:42:22.5 |
HIP 36897 |
13.13 |
| 2026-09-21 00:00 |
07:34:47.88 |
-31:42:39.3 |
HIP 36897 |
13.34 |
| 2026-09-21 12:00 |
07:34:48.50 |
-31:42:56.1 |
HIP 36897 |
13.56 |
| 2026-09-22 00:00 |
07:34:49.11 |
-31:43:13.0 |
HIP 36897 |
13.78 |
| 2026-09-22 12:00 |
07:34:49.71 |
-31:43:29.9 |
HIP 36897 |
14.01 |
| 2026-09-23 00:00 |
07:34:50.30 |
-31:43:46.8 |
HIP 36897 |
14.24 |
| 2026-09-23 12:00 |
07:34:50.87 |
-31:44:03.8 |
HIP 36897 |
14.48 |
| 2026-09-24 00:00 |
07:34:51.43 |
-31:44:20.9 |
HIP 36897 |
14.72 |
| 2026-09-24 12:00 |
07:34:51.98 |
-31:44:37.9 |
HIP 36897 |
14.97 |
| 2026-09-25 00:00 |
07:34:52.51 |
-31:44:55.0 |
HIP 36897 |
15.22 |
| 2026-09-25 12:00 |
07:34:53.03 |
-31:45:12.1 |
HIP 36897 |
15.47 |
| 2026-09-26 00:00 |
07:34:53.53 |
-31:45:29.3 |
HIP 36897 |
15.72 |
| 2026-09-26 12:00 |
07:34:54.03 |
-31:45:46.5 |
HIP 36897 |
15.98 |
| 2026-09-27 00:00 |
07:34:54.50 |
-31:46:03.8 |
HIP 36897 |
16.24 |
| 2026-09-27 12:00 |
07:34:54.97 |
-31:46:21.0 |
HIP 36897 |
16.51 |
| 2026-09-28 00:00 |
07:34:55.42 |
-31:46:38.3 |
HIP 36897 |
16.77 |
| 2026-09-28 12:00 |
07:34:55.86 |
-31:46:55.7 |
HIP 36897 |
17.04 |
| 2026-09-29 00:00 |
07:34:56.28 |
-31:47:13.0 |
HIP 36897 |
17.31 |
| 2026-09-29 12:00 |
07:34:56.69 |
-31:47:30.4 |
HIP 36897 |
17.58 |
| 2026-09-30 00:00 |
07:34:57.09 |
-31:47:47.8 |
HIP 36897 |
17.86 |
| 2026-09-30 12:00 |
07:34:57.47 |
-31:48:05.3 |
HIP 36897 |
18.13 |
| 2026-10-01 00:00 |
07:34:57.84 |
-31:48:22.7 |
HIP 36897 |
18.41 |
| 2026-10-01 12:00 |
07:34:58.20 |
-31:48:40.2 |
HIP 36897 |
18.69 |
| 2026-10-02 00:00 |
07:34:58.54 |
-31:48:57.7 |
HIP 36897 |
18.97 |
| 2026-10-02 12:00 |
07:34:58.87 |
-31:49:15.2 |
HIP 36897 |
19.25 |
| 2026-10-03 00:00 |
07:34:59.18 |
-31:49:32.8 |
HIP 36897 |
19.53 |
| 2026-10-03 12:00 |
07:34:59.48 |
-31:49:50.3 |
HIP 36897 |
19.81 |
| 2026-10-04 00:00 |
07:34:59.77 |
-31:50:07.9 |
HIP 36897 |
20.10 |
| 2026-10-04 12:00 |
07:35:00.04 |
-31:50:25.5 |
HIP 36897 |
20.39 |
| 2026-10-05 00:00 |
07:35:00.29 |
-31:50:43.1 |
HIP 36897 |
20.67 |
| 2026-10-05 12:00 |
07:35:00.54 |
-31:51:00.7 |
HIP 36897 |
20.96 |
| 2026-10-06 00:00 |
07:35:00.76 |
-31:51:18.3 |
HIP 36897 |
21.25 |
| 2026-10-06 12:00 |
07:35:00.98 |
-31:51:36.0 |
HIP 36897 |
21.54 |
| 2026-10-07 00:00 |
07:35:01.18 |
-31:51:53.6 |
HIP 36897 |
21.83 |
| 2026-10-07 12:00 |
07:35:01.36 |
-31:52:11.3 |
HIP 36897 |
22.12 |
| 2026-10-08 00:00 |
07:35:01.53 |
-31:52:29.0 |
HIP 36948 |
22.03 |
| 2026-10-08 12:00 |
07:35:01.69 |
-31:52:46.6 |
HIP 36948 |
21.75 |
| 2026-10-09 00:00 |
07:35:01.83 |
-31:53:04.3 |
HIP 36948 |
21.48 |
| 2026-10-09 12:00 |
07:35:01.96 |
-31:53:22.0 |
HIP 36948 |
21.20 |
| 2026-10-10 00:00 |
07:35:02.07 |
-31:53:39.6 |
HIP 36948 |
20.93 |
| 2026-10-10 12:00 |
07:35:02.17 |
-31:53:57.3 |
HIP 36948 |
20.66 |
| 2026-10-11 00:00 |
07:35:02.25 |
-31:54:15.0 |
HIP 36948 |
20.39 |