P/2010 A2 (LINEAR)
The dust/debris structure is still very constant, 37 arc sec in
PA 278.
The
image of the Hubble Space Telescope of January,29 2010
is showing the corresponding asteroids on the Eastern part of the dust.
Since this image of the Hubble Space Telescope was taken it is clear,
that the dust/debris/boulder structure is directed relatively to the Sun (Sun Pos.Angle PA 292.3 at Jan, 19
2010).
This means, that the dust/debris of P/2010 A2 (LINEAR) is not
comparable with a "normal" dust tail of a comet, which is normally directed
roughly vice versa to
the Sun Pos. Angle. The ejected material of the collision should be more compact
than comet material.
But it seems, that the dust/debris of P/2010 A2 is influenced
by both the
solar wind and gravitational forces anyway.
At the moment of the assumed collision of two asteroids, the
direction of the dust/debris is influenced by the impact event, off course.
But it is very interesting, that the remaining dust/debris complex is still very constant in shape and orientation.
Hiroki Akisawa from Japan calculated
by Bessel-Bredikhin theory and fitted
for this image.
Description of his diagram:
Yahoo Comets ML
(C) 2010-03-11 by Bernhard Haeusler, Maidbronn, Germany image frozen on stars and dust structure
20 x 3 min. exposure,
2010-03-11 UT 20:32, 12" SCT
f-5.65 + CCD ST10XME
head of the
dust structure on the left: 19.3 mag, "tail": 37" in PA 278�
The Sun Pos.Angle at the time of the exposure was PA 275.7 (See:
HORIZON
Query, QUANTITIES=1,9,16)
Gif animation 20 x 3 minutes in reality, foreshortend to
1.8 seconds
P/2010 A2 in the center left, asteroid 19610 Arthurdent (17.4 mag) on the right upper
corner
magnification 3x
The
constitution of the dust/debris/
I.e. the end of C/1999 S4
(and probably the actual end of C/2009 O2 too) was going
on very fast.
The next opposition of P/2010 A2 will occur in May/June 2011. This will be
an
interesting opportunity the take more images and to check,
if the structure has changed. Maybe the Solar Wind
will not disperse the destroyed material of the collided
asteroids until next year.
MPC observation computed with Astrometrica MPC2010-E50 of March, 12 2010
COD B82
OBS Bernhard Haeusler
TEL 0.30-m Schmidt-Cassegrain + CCD
NET CMC-14
PK10A020 KC2010 03 11.86046 06 51 59.13 +24 21 57.0 19.3 N B82
PK10A020 KC2010 03 11.87791 06 52 00.30 +24 21 50.6 18.9 N B82
PK10A020 KC2010 03 11.89534 06 52 01.09 +24 21 44.4 18.9 N B82
Gauss curve produced by Astrometrica. The total PSF is using the
aperture circle of 3 x 3
pixel around the brightest pixel.
You see the Gauss curve right as the computed ideal line and the real pixels
contributed around the ideal line.
The Fit RMS is the deviation from the ideal line (inlay under the Gauss curve).
Photometry computed with FOCAS II, using the Multibox method:
COD B82
OBS Bernhard Haeusler
CATALOG: USNO A2.0 / CMC-14 - BAND: R
10x10 20x20 30x30 40x40 50x50 60x60
SNR SB COD
OBJECT DATE
TIME +/-
+/- +/-
+/- +/-
+/- N FWHM CAT
------------ ---------- -------- ----- ----- -----
----- ----- ----- ---- ---- ---
P/2010 A2 11/03/2010 21:10:11 19.33
18.92 19.02 19.07 18.96 18.79 3.8 22.6 B82
P/2010 A2 11/03/2010 21:10:11*
0.17 0.23 0.23 0.24 0.35 0.40 5 5.6 CMC
FoCAs II - 07/01/2009-b
FOCAS II is a tool for photometry on the base of data coming from Astrometrica. Focas is basically using the .LOG file of Astrometrica.
Explanation of the FOCAS II table headings:
Object, date and time are self-explaining.
10x10, 20x20 ... 60x60 are the measured magnitudes according to the aperture
sizes of photometry in arc sec (circle).
SNR is the
Signal-to-noise ratio for aperture photometry (calculator).
SB is the magnitude of the faintest star on the image matching with the used
star catalogue. This is not the faintest star of the image!
COD is the MPC Code of the
observatory.
second line:
+/- are the precisions of the measurements.
N is the number of the used images for the measurements.
FWHM is the
Full-Width Half-Maximum of the total PSF: Measure of the seeing.
CAT is the used star catalog in Astrometrica. x
links:
http://astrosurf.com/cometas-obs/index_i.htm Visual and CCD Observations and images from the "Cometas Obs" mailing list, using the Focas II format
es.groups.yahoo.com/group/Cometas_Obs The Spanish comet observation group in Yahoo