C/1995 Q1 (Bradfield)

Metadata

Parameter Value
Designation C/1995 Q1 (Bradfield)
Type C
Perihelion (tp_cal, UTC) 1995-08-31T10:02:38.832000Z
Orbit solution date (soln_date, UTC) 2021-04-15T23:29:47Z
Obs used 156
NEO -
M1 9.600
K1 16.500
PC -
Osculating Elements
Parameter Value
Epoch (epoch_cal, TDB) 1995-10-23.0000000
e 0.99802567
q (au) 0.436387
a (au) 221.030541
i (deg) 147.394301
Ω (om, deg) 178.054729
ω (w, deg) 331.161810
M (ma, deg) 0.015771

Magnitude

C/1995 Q1 (Bradfield) · Magnitude (Full range)

Scatter + Global Linear

$$ M_a = (7.436 + 4.304\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

Model Parameters

Parameter Value
H0 7.436
n 4.304
gf 0.800
gb -0.500
k 1.000
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
1995-08-18 1995-08-30 -1.3532 +0.497
1995-09-23 1995-10-08 -3.7552 -0.310
1995-10-08 1995-10-17 +7.6437 -0.177
1995-10-17 1995-11-21 +1.5080 -0.252
1995-11-21 1995-12-13 +13.9429 -3.253
1995-12-13 1996-02-19 +6.5452 -1.275

log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)

Ephemeris

Date/Time (UTC) RA (J2000) Dec (J2000) Nearest HIP Dist from HIP (arcmin)
2026-05-12 00:00 01:30:13.06 +30:14:28.0 HIP 6998 5.66
2026-05-12 12:00 01:30:15.12 +30:14:42.7 HIP 6998 6.03
2026-05-13 00:00 01:30:17.18 +30:14:57.4 HIP 6998 6.42
2026-05-13 12:00 01:30:19.23 +30:15:12.2 HIP 6998 6.82
2026-05-14 00:00 01:30:21.27 +30:15:27.0 HIP 6998 7.24
2026-05-14 12:00 01:30:23.30 +30:15:41.9 HIP 6998 7.67
2026-05-15 00:00 01:30:25.32 +30:15:56.8 HIP 6998 8.10
2026-05-15 12:00 01:30:27.33 +30:16:11.7 HIP 6998 8.54
2026-05-16 00:00 01:30:29.33 +30:16:26.7 HIP 6998 8.99
2026-05-16 12:00 01:30:31.32 +30:16:41.7 HIP 6998 9.45
2026-05-17 00:00 01:30:33.30 +30:16:56.8 HIP 6998 9.90
2026-05-17 12:00 01:30:35.27 +30:17:11.9 HIP 6998 10.36
2026-05-18 00:00 01:30:37.24 +30:17:27.0 HIP 6998 10.82
2026-05-18 12:00 01:30:39.19 +30:17:42.1 HIP 6998 11.28
2026-05-19 00:00 01:30:41.13 +30:17:57.3 HIP 6998 11.75
2026-05-19 12:00 01:30:43.06 +30:18:12.5 HIP 6998 12.21
2026-05-20 00:00 01:30:44.97 +30:18:27.7 HIP 6998 12.68
2026-05-20 12:00 01:30:46.88 +30:18:43.0 HIP 6998 13.14
2026-05-21 00:00 01:30:48.78 +30:18:58.3 HIP 6998 13.61
2026-05-21 12:00 01:30:50.66 +30:19:13.6 HIP 6998 14.07
2026-05-22 00:00 01:30:52.54 +30:19:28.9 HIP 6998 14.54
2026-05-22 12:00 01:30:54.40 +30:19:44.3 HIP 6998 15.00
2026-05-23 00:00 01:30:56.25 +30:19:59.6 HIP 6998 15.46
2026-05-23 12:00 01:30:58.09 +30:20:15.0 HIP 6998 15.92
2026-05-24 00:00 01:30:59.92 +30:20:30.5 HIP 6998 16.39
2026-05-24 12:00 01:31:01.73 +30:20:45.9 HIP 6998 16.85
2026-05-25 00:00 01:31:03.54 +30:21:01.3 HIP 6998 17.30
2026-05-25 12:00 01:31:05.33 +30:21:16.8 HIP 6998 17.76
2026-05-26 00:00 01:31:07.11 +30:21:32.3 HIP 7123 18.08
2026-05-26 12:00 01:31:08.87 +30:21:47.8 HIP 7123 17.68
2026-05-27 00:00 01:31:10.63 +30:22:03.3 HIP 7123 17.27
2026-05-27 12:00 01:31:12.37 +30:22:18.8 HIP 7123 16.88
2026-05-28 00:00 01:31:14.10 +30:22:34.4 HIP 7123 16.48
2026-05-28 12:00 01:31:15.81 +30:22:49.9 HIP 7123 16.09
2026-05-29 00:00 01:31:17.52 +30:23:05.5 HIP 7123 15.71
2026-05-29 12:00 01:31:19.21 +30:23:21.0 HIP 7123 15.32
2026-05-30 00:00 01:31:20.88 +30:23:36.6 HIP 7123 14.95
2026-05-30 12:00 01:31:22.55 +30:23:52.2 HIP 7123 14.58
2026-05-31 00:00 01:31:24.20 +30:24:07.7 HIP 7123 14.21
2026-05-31 12:00 01:31:25.83 +30:24:23.3 HIP 7123 13.85
2026-06-01 00:00 01:31:27.46 +30:24:38.9 HIP 7123 13.49
2026-06-01 12:00 01:31:29.06 +30:24:54.5 HIP 7123 13.14
2026-06-02 00:00 01:31:30.66 +30:25:10.1 HIP 7123 12.79