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IDMC 2014 17 Dec 2014 Shashikiran Ganesh ([email protected])
Shashikiran GaneshSonam Arora, Sunil Chandra, Kumar Venkataramani, Navpreet Kaur, Ashish Mishra
Kiran S Baliyan, Umesh C Joshi
Astronomy & Astrophysics DivisionPhysical Research Laboratory
Ahmedabad
e-mail: [email protected]
17th December 2014
Observations of cometary dust from Mount Abu
IDMC 2014 17 Dec 2014 Shashikiran Ganesh ([email protected])
Courtesy of Rakesh Rao
Mt Abu IR Observatory campus
IDMC 2014 17 Dec 2014 Shashikiran Ganesh ([email protected])
PRL telescopes
Observatory at Mount Abu : 1.2m aperture
Robotic telescope at Mount Abu : 50cm aperture
Instruments : 1.2m : Optical photo and imaging polarimeters Narrow band Comet Filter Set (Hale-Bopp) 1.2m : NIR imaging and spectroscopy (0.8 to 2.2micron) 50cm : large format imaging/polarimetry (R)
IDMC 2014 17 Dec 2014 Shashikiran Ganesh ([email protected])
Comet C/2012 S1 (ISON)
Sun grazing comet discovered at a large distance away
Anticipated to be 'Comet of the Century'
Didn't survive perihelion passage (29th November 2013)
IDMC 2014 17 Dec 2014 Shashikiran Ganesh ([email protected])
- Sonam Arora-Rao (M.Tech thesis - submitted)
IDMC 2014 17 Dec 2014 Shashikiran Ganesh ([email protected])
Comet ISON – 14th November 2013 LS processed
- Sonam Arora-Rao (M.Tech thesis - submitted)
IDMC 2014 17 Dec 2014 Shashikiran Ganesh ([email protected])
11th November 2013 14th November 15th November Comet ISON C/2012 S1 - LS processed
- Sonam Arora-Rao (M.Tech thesis - submitted)
IDMC 2014 17 Dec 2014 Shashikiran Ganesh ([email protected])
Comet C/2013 R1 (Lovejoy)
Polarimetry using 50cm telescope (3 position polaroid method)
IDMC 2014 17 Dec 2014 Shashikiran Ganesh ([email protected])
Comet C/2013 R1 (Lovejoy)
- Sonam Arora-Rao (M.Tech thesis - submitted)
IDMC 2014 17 Dec 2014 Shashikiran Ganesh ([email protected])
Comet C/2013 A1 (SidingSpring)
Nucleus diameter earlier estimated to be 700m
Encounter with Mars on 19th October 2014
No collision – closest distance 132000km
Pass on day side i.e. between Sun and Mars
Mars passed within 27000km of comet's orbital path 100mins after closest approach
IDMC 2014 17 Dec 2014 Shashikiran Ganesh ([email protected])
Orbital plane
Sun
Ganesh, Sinha, PLANEX Newsletter January 2014
IDMC 2014 17 Dec 2014 Shashikiran Ganesh ([email protected])
PRL Observations of C/2013 A1 (SidingSpring) during January 2014
Imaging in R broad band filter on 1.2m telescope
Date of observation : 4th Jan 2014 UT : 15:40:15.43 RA = 03:23:57.07 DEC = -38:36:23.9 86 images of 40sec each Camera: 1K x 1K LN2 CCD
IDMC 2014 17 Dec 2014 Shashikiran Ganesh ([email protected])
PRL Observations of C/2013 A1 (SidingSpring) during January 2014
Imaging in R broad band filter on 1.2m telescope
Date of observation : 4th Jan 2014 UT : 15:40:15.43 RA = 03:23:57.07 DEC = -38:36:23.9 86 images of 40sec each Distance from Sun = 3.64AU Distance from Earth = 3.94AU Size of coma : 40k km (dia)
IDMC 2014 17 Dec 2014 Shashikiran Ganesh ([email protected])
PRL Observations of C/2013 A1 (SidingSpring) during January 2014
Direct image LS processed image with contour LS processed image
LS: Larson-Sekanina Technique to bring out jets and shells in presence of bright coma
IDMC 2014 17 Dec 2014 Shashikiran Ganesh ([email protected])
5th October 2014
Comet is moving against the Galactic plane, as seen from Earth.
IDMC 2014 17 Dec 2014 Shashikiran Ganesh ([email protected])
1st to 5th October 2014
Apparent magnitude faded from 12.97 to 13.1 over above period (R band photometry)
IDMC 2014 17 Dec 2014 Shashikiran Ganesh ([email protected])
Imaging polarimeter
Imaging polarimetry on 1.2m telescope in BVRI & SDSS and narrow bands (12 filters)
python scripts for processing of the data
IDMC 2014 17 Dec 2014 Shashikiran Ganesh ([email protected])
Imaging polarimeter
IDMC 2014 17 Dec 2014 Shashikiran Ganesh ([email protected])
IDMC 2014 17 Dec 2014 Shashikiran Ganesh ([email protected])
100% Polarization with Glan prism
IDMC 2014 17 Dec 2014 Shashikiran Ganesh ([email protected])
IDMC 2014 17 Dec 2014 Shashikiran Ganesh ([email protected])
Getting back to comets....
IDMC 2014 17 Dec 2014 Shashikiran Ganesh ([email protected])
Comet C/2014 Q2 (Lovejoy)
Nearly naked eye visible right now..
Observed with imaging polarimeter on 1.2m telescope on 24th November 2014 (R band)
Expected to brighten as it approaches perihelion (Jan 2015)
Nearest to earth on 7th Jan 2015
Observations with 50cm telescope also on going
IDMC 2014 17 Dec 2014 Shashikiran Ganesh ([email protected])
Comet C/2014 Q2 (Lovejoy)
24th November 2014 (R band imaging polarimetry)
IDMC 2014 17 Dec 2014 Shashikiran Ganesh ([email protected])
Comet C/2014 Q2 (Lovejoy)
24th November 2014 (R band imaging polarimetry)
IDMC 2014 17 Dec 2014 Shashikiran Ganesh ([email protected])
Summary
Comets are extremely dynamic objects
Variations seen in small spatial and time scales
Good coverage needed in multiple filtersover wide phase angle range
Need : bright comets or larger telescopes
coordinated observations with multiple telescopes and capabilities