Observations of cometary dust from Mount Abuidmc2014/presentation/C15.pdf · - Sonam Arora-Rao (M.Tech thesis - submitted) IDMC 2014 17 Dec 2014 Shashikiran Ganesh ([email protected])

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

mailto:[email protected]



Courtesy of Rakesh Rao

Mt Abu IR Observatory campus



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)



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)



- Sonam Arora-Rao (M.Tech thesis - submitted)



Comet ISON – 14th November 2013 LS processed




11th November 2013 14th November 15th November Comet ISON C/2012 S1 - LS processed




Comet C/2013 R1 (Lovejoy)

Polarimetry using 50cm telescope (3 position polaroid method)



Comet C/2013 R1 (Lovejoy)




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



Orbital plane

Sun

Ganesh, Sinha, PLANEX Newsletter January 2014



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




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)




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



5th October 2014

Comet is moving against the Galactic plane, as seen from Earth.



1st to 5th October 2014

Apparent magnitude faded from 12.97 to 13.1 over above period (R band photometry)



Imaging polarimeter

Imaging polarimetry on 1.2m telescope in BVRI & SDSS and narrow bands (12 filters)

python scripts for processing of the data



Imaging polarimeter





100% Polarization with Glan prism





Getting back to comets....



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




24th November 2014 (R band imaging polarimetry)




24th November 2014 (R band imaging polarimetry)



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



Thanks!


Documents

Observations of cometary dust from Mount Abuidmc2014/presentation/C15.pdf · - Sonam Arora-Rao (M.Tech thesis - submitted) IDMC 2014 17 Dec 2014 Shashikiran Ganesh ([email protected])