| Parameter |
Value |
| Designation |
C/2001 Q4 (NEAT) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2004-05-15T23:10:38.346240Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:30:11Z |
| Obs used |
2617 |
| NEO |
- |
| M1 |
8.000 |
| K1 |
6.750 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2004-05-15.0000000 |
| e |
1.00068805 |
| q (au) |
0.961960 |
| a (au) |
-1398.092298 |
| i (deg) |
99.642634 |
| Ω (om, deg) |
210.278440 |
| ω (w, deg) |
1.204371 |
| M (ma, deg) |
-0.000018 |
Magnitude
Scatter + Global Linear
$$
M_a = (5.940 + 4.075\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
5.940 |
| n |
4.075 |
| gf |
1.000 |
| gb |
-0.500 |
| k |
0.817 |
| δ90 |
9.991 |
| 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 |
| 2001-08-24 |
2004-03-09 |
-1.4351 |
-0.245 |
| 2004-03-09 |
2004-03-31 |
+6.4597 |
-1.163 |
| 2004-03-31 |
2004-05-15 |
-10.1442 |
+0.669 |
| 2004-05-15 |
2004-10-18 |
-1.2519 |
+0.669 |
| 2004-10-18 |
2006-08-18 |
+0.3692 |
+0.505 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-03-26 00:00 |
01:37:24.69 |
+26:50:34.3 |
HIP 7677 |
22.46 |
| 2026-03-26 12:00 |
01:37:27.33 |
+26:50:41.8 |
HIP 7677 |
22.03 |
| 2026-03-27 00:00 |
01:37:29.97 |
+26:50:49.4 |
HIP 7677 |
21.61 |
| 2026-03-27 12:00 |
01:37:32.62 |
+26:50:57.2 |
HIP 7677 |
21.20 |
| 2026-03-28 00:00 |
01:37:35.28 |
+26:51:05.0 |
HIP 7677 |
20.79 |
| 2026-03-28 12:00 |
01:37:37.95 |
+26:51:13.0 |
HIP 7677 |
20.40 |
| 2026-03-29 00:00 |
01:37:40.62 |
+26:51:21.2 |
HIP 7677 |
20.02 |
| 2026-03-29 12:00 |
01:37:43.30 |
+26:51:29.4 |
HIP 7677 |
19.65 |
| 2026-03-30 00:00 |
01:37:45.99 |
+26:51:37.8 |
HIP 7677 |
19.29 |
| 2026-03-30 12:00 |
01:37:48.68 |
+26:51:46.3 |
HIP 7677 |
18.95 |
| 2026-03-31 00:00 |
01:37:51.38 |
+26:51:54.9 |
HIP 7677 |
18.62 |
| 2026-03-31 12:00 |
01:37:54.09 |
+26:52:03.7 |
HIP 7677 |
18.31 |
| 2026-04-01 00:00 |
01:37:56.80 |
+26:52:12.5 |
HIP 7677 |
18.01 |
| 2026-04-01 12:00 |
01:37:59.52 |
+26:52:21.5 |
HIP 7677 |
17.74 |
| 2026-04-02 00:00 |
01:38:02.24 |
+26:52:30.7 |
HIP 7677 |
17.48 |
| 2026-04-02 12:00 |
01:38:04.97 |
+26:52:39.9 |
HIP 7677 |
17.24 |
| 2026-04-03 00:00 |
01:38:07.70 |
+26:52:49.3 |
HIP 7677 |
17.02 |
| 2026-04-03 12:00 |
01:38:10.44 |
+26:52:58.7 |
HIP 7677 |
16.82 |
| 2026-04-04 00:00 |
01:38:13.19 |
+26:53:08.3 |
HIP 7677 |
16.65 |
| 2026-04-04 12:00 |
01:38:15.94 |
+26:53:18.0 |
HIP 7677 |
16.50 |
| 2026-04-05 00:00 |
01:38:18.69 |
+26:53:27.9 |
HIP 7677 |
16.37 |
| 2026-04-05 12:00 |
01:38:21.45 |
+26:53:37.8 |
HIP 7677 |
16.27 |
| 2026-04-06 00:00 |
01:38:24.21 |
+26:53:47.9 |
HIP 7677 |
16.20 |
| 2026-04-06 12:00 |
01:38:26.98 |
+26:53:58.0 |
HIP 7677 |
16.15 |
| 2026-04-07 00:00 |
01:38:29.75 |
+26:54:08.3 |
HIP 7677 |
16.13 |
| 2026-04-07 12:00 |
01:38:32.53 |
+26:54:18.7 |
HIP 7677 |
16.13 |
| 2026-04-08 00:00 |
01:38:35.31 |
+26:54:29.2 |
HIP 7677 |
16.17 |
| 2026-04-08 12:00 |
01:38:38.09 |
+26:54:39.9 |
HIP 7677 |
16.23 |
| 2026-04-09 00:00 |
01:38:40.87 |
+26:54:50.6 |
HIP 7677 |
16.32 |
| 2026-04-09 12:00 |
01:38:43.66 |
+26:55:01.4 |
HIP 7677 |
16.43 |
| 2026-04-10 00:00 |
01:38:46.45 |
+26:55:12.4 |
HIP 7677 |
16.57 |
| 2026-04-10 12:00 |
01:38:49.25 |
+26:55:23.4 |
HIP 7677 |
16.74 |
| 2026-04-11 00:00 |
01:38:52.04 |
+26:55:34.6 |
HIP 7677 |
16.93 |
| 2026-04-11 12:00 |
01:38:54.84 |
+26:55:45.9 |
HIP 7677 |
17.15 |
| 2026-04-12 00:00 |
01:38:57.64 |
+26:55:57.3 |
HIP 7677 |
17.39 |
| 2026-04-12 12:00 |
01:39:00.44 |
+26:56:08.7 |
HIP 7677 |
17.65 |
| 2026-04-13 00:00 |
01:39:03.25 |
+26:56:20.3 |
HIP 7677 |
17.93 |
| 2026-04-13 12:00 |
01:39:06.05 |
+26:56:32.0 |
HIP 7677 |
18.24 |
| 2026-04-14 00:00 |
01:39:08.86 |
+26:56:43.8 |
HIP 7677 |
18.56 |
| 2026-04-14 12:00 |
01:39:11.67 |
+26:56:55.7 |
HIP 7677 |
18.91 |
| 2026-04-15 00:00 |
01:39:14.48 |
+26:57:07.7 |
HIP 7677 |
19.27 |
| 2026-04-15 12:00 |
01:39:17.29 |
+26:57:19.7 |
HIP 7677 |
19.65 |
| 2026-04-16 00:00 |
01:39:20.10 |
+26:57:31.9 |
HIP 7677 |
20.04 |