Collaborative Occultation Resources and Archive (CORA)

2023-11-07 / UCAC4 546-017448 / (4489) Dracius

#	OBS	Observer	Occ	Meth.	Instr.	CC	TSRC	UT1	UT2	UT3	UT4	UT2E	UT3E	Dur.	Chrd
1	show	Oscar Canales	O+	VID	M280	ES	GPS	20:47:11	20:49:11.75	20:49:18.07	20:51:11	0.08	0.08	6.32	70.8
2	show	Florian Signoret	O+	VID	T200	FR	GPS	20:38:31	20:48:49.270	20:48:58.970	20:53:51	0.100	0.100	9.70	108.6

UT1/UT4: Begin/End of observation | UT2/UT3: Begin/End of occultation | Dur: Reported duration in seconds | Chrd: Corresponding chord length in km | More

2 observations found in db: sodis

Available (probably) matching predictions (click on the link to switch):

JPL#65 : d8a24e9b-60dc-4e81-b170-937f67837300 [db: observed]

JPL#71 : b7d99260-c33f-11ef-5276-5352fcfd3ee4 [db: observed]

Using prediction d8a24e9b-60dc-4e81-b170-937f67837300 for map and profile fit

Get observations as KML file (reduced site location resolution)

Ellipse and circular profile fits to the timings (chords)

Auto-Fit Result:
X0,Y0 = -724.6, 90.3 km
Circular diameter = 116 km

From 2 chords (VID)

You can enter space separated chord numbers (example: 11 4 8) or a method like VIS to ignore all visual timings, or a time source like RAD and NTP (but not GPS).
If the plot disappears, then there are less than 2 chords left (too much ignored, go back with browser).

Check SiMDA for size and mass data.

Check Johnston Archive for satellites.

Sky projection (artificial light) for occ. time: 2023-11-07, 20:48 UT (JD = 2460256.367)

DAMIT	Q	P (h)	λ, β	JD0	JD-JD0	φ0	Version	Modified	Vol-equiv D	Cmnt
# 4185	1.0	12.584	136°, -27°	2.451136e6	9120.4	0.0°	None	2019-09-26	not scaled	2019-05-07

Q: model quality flag (0-5, 5=highest) | P: rotation period | λ,β: ecl. lon. and lat. of spin axis (J2000) | JD: initial time (epoch) | φ0: initial rotation angle for JD0

Image size: 300px. Transparent image background for copy & paste

Map with groundtrack and observer stations

Event Details
Occultation UUID [and DB] : d8a24e9b-60dc-4e81-b170-937f67837300 [observed] Occultation Date + Time : 2023-11-07 at 20:40:40 UT +/- 0.08 min [1] Object Designation : (4489) Dracius Orbit Class : JTRO Star Designation : GDR3 3397890464866839168 Star Coordinates (ICRF) : RA = 05 39 04.2495, DE = +19 00 38.022 [2] Star Magnitudes : G = 11.27 mag, RP = 10.66 mag, BP = 11.7 mag Object Magnitude : V = 16.19 mag Estimated Magnitude Drop : 4.9 mag Estimated Max. Duration : 8.3 sec Object Mean Diameter : 92.9 km (src: astorb) Speed of the shadow : 11.2 km/s Elongation to Moon & Sun : 78° (sunlit = 27%), Sun = 140° Cross-track uncertainty : 8.0 mas = 23 km = 0.26 path-width (1-sig) RUWE and duplicate source : 5.35 mas, dup.src = 0 (0:false, 1:true) Ephemeris Reference : JPL#65 [1] time t0 of closest geocentric approach c/a, [2] including proper motion until t0

Event Details

 Occultation UUID [and DB] : d8a24e9b-60dc-4e81-b170-937f67837300 [observed]

 Occultation Date + Time   : 2023-11-07 at 20:40:40 UT +/- 0.08 min  [1]
 Object Designation        : (4489) Dracius
 Orbit Class               : JTRO
 Star Designation          : GDR3 3397890464866839168
 Star Coordinates (ICRF)   : RA = 05 39 04.2495, DE = +19 00 38.022  [2]
 Star Magnitudes           : G = 11.27 mag, RP = 10.66 mag, BP = 11.7 mag
 Object Magnitude          : V = 16.19 mag
 Estimated Magnitude Drop  : 4.9 mag
 Estimated Max. Duration   : 8.3 sec
 Object Mean Diameter      : 92.9 km  (src: astorb)
 Speed of the shadow       : 11.2 km/s
 Elongation to Moon & Sun  : 78° (sunlit = 27%), Sun = 140°
 Cross-track uncertainty   : 8.0 mas = 23 km = 0.26 path-width (1-sig)
 RUWE and duplicate source : 5.35 mas, dup.src = 0  (0:false, 1:true)

 Ephemeris Reference       : JPL#65

 
 [1] time t0 of closest geocentric approach c/a, [2] including proper motion until t0

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