Close Approach of Asteroid 2003 DZ15

M.P.E.C. 2013-O29, issued on 2013 July 20, reports the recovery of the Apollo asteroid 2003 DZ15 (magnitude 18) by F51 Pan-STARRS 1, Haleakala, on images taken on July 19.4 with a 1.8-m Ritchey-Chretien + CCD.

2003 DZ15 was discovered on February 2003 by 608 Haleakala-NEAT/MSSS and it has an estimated size of 95 m - 210 m (based on the object's absolute magnitude H=22.2) and it will have a close approach with Earth at about 9.1 LD (Lunar Distances = ~384,000 kilometers) or 0.0233 AU (1 AU = ~150 million kilometers) at 0037 UT on 2013 July 30. This asteroid will reach the peak magnitude ~16.5 on 29 and 30 July 2013. This is its closest approach to the Earth for this century, although it will make a pass nearly as close to the Earth in 2057 on February 12th.

We performed some follow-up measurements of this object, from the Q62 ITelescope network (Siding Spring, AU) on  2013, July 28.6, through a 0.50-m f/6.8 astrograph + CCD + focal reducer. Below you can see our image, single 120-second exposure, taken with the asteroid at magnitude ~16.6 and moving at ~40.80 "/min. At the moment of the close approach 2003 DZ15 will move at ~52 "/min. Click on the image below to see a bigger version (the asteroid is trailed in the image due to its fast speed).

Below you can see a short animation showing the movement of 2003 DZ15 (three consecutive 120-second exposure). Click on the thumbnail for a bigger version:

by Ernesto Guido & Nick Howes

SUPERNOVA 2013ej IN M74

Following the posting on the Central Bureau's Transient Object Confirmation Page about a possible Supernova in M74 (TOCP Designation: PSN J01364816+1545310) we performed some follow-up of this object remotely through a 0.43-m f/6.8 astrograph + CCD of iTelescope network (MPC Code  Q62 - Siding Spring, AU).

On our images taken on July 27.7, 2013 we can confirm the presence of an optical counterpart with R-filtered CCD magnitude 13.0 and V-filtered CCD magnitude 12.6 at coordinates:

R.A. = 01 36 48.20, Decl.= +15 45 31.0

(equinox 2000.0; UCAC-3 catalogue reference stars).

Our annotated confirmation image (single 120-second exposures under a cloudy sky):

An animation showing a comparison between our confirmation image and the archive POSS2/UKSTU plate (R Filter - 1990). Click on the thumbnail for a bigger version:

UPDATE - July 28, 2013

According to CBET 3606 this transient has been discovered by LOSS supernova survey on unfiltered KAIT images obtained on July 25.45.

D. D. Balam, Dominion Astrophysical Observatory, National Research Council of Canada; M. L. Graham, Las Cumbres Observatory Global Telescope, University of California at Santa Barbara; and E. Y. Hsiao, Las Campanas Observatory, report that a spectrogram (range 369-700 nm, resolution 0.3 nm) of PSN J01364816+1545310 = SN 2013ej, obtained on July 27.41 UT with the 1.82-m Plaskett Telescope of the National Research Council of Canada, shows a moderately blue continuum with weak Balmer emission lines showing P-Cyg profiles, suggesting that this is a core-collapse event.

This young type II supernova has been officially designated 2013ej.

This is the third supernova in M74 over the last eleven years (previous SN were: SN 2002ap and SN 2003gd).

Other info about this bright supernova are available through Atel (The Astronomer's Telegram):

ATel 5228: Spectroscopic classification for PSN J01364816+1545310 in M74 with FLOYDS at Faulkes Telescope South http://bit.ly/14loD8R  

ATel 5229: The Probable Progenitor of PSN J01364816+1545310 in M74 http://bit.ly/1bvU8XF

ATel 5230: Possible Spitzer Counterpart of PSN J01364816+1545310 http://bit.ly/12tjukY

Below you can see our image of supernova 2013ej IN M74 obtained on 2013 July 28.7. Click on it for a bigger version. (R-magnitude 12.8; B-magnitude 12.0)

by Ernesto Guido & Nick Howes

Observations of the Herschel Space Observatory

The Herschel Space Observatory was a European Space Agency-built and -operated space observatory, active from 2009 to 2013. It was studying the Universe by the light of the far-infrared and submillimeter portions of the spectrum revealing new information about the earliest, most distant stars and galaxies, as well as those closer to home in space and time. It has also taken a unique look at our own solar system. Herschel Space Observatory was the largest infrared telescope ever launched, carrying a single 3.5-metre mirror.

In the afternoon of April 29, 2013 Herschel ran out of liquid helium. To declare end-of-helium (EoHe) a number of key temperature sensor upper limits had been defined, and with two of them attained, EoHe had formally been reached. Herschel has made over 35000 scientific observations, amassing more than 25000 hours of science data from about 600 observing programmes. Finally on June 17, 2013, engineers for the Herschel space telescope sent final commands to put the decommissioned observatory from its orbit around the L2 point 1.5 million kilometres from the Earth into its “graveyard” heliocentric parking orbit.

Last week we decide to follow-up the "Herschel Space Observatory" in his new orbit using the Faulkes Telescopes (2.0-m f/10.0 Ritchey-Chretien + CCD - operated by Las Cumbres Observatory Global Telescope Network).  In fact, determining an accurate orbit now is important, because its increasing distance will make it fainter and much harder to keep track of in the intervening years.

"The observation was a particular challenge as the final manoeuvres made by the ESA flight control team resulted in the observatory being at a slightly different position on the sky compared to that predicted by existing orbital data".

We successfully imaged the Herschel on 26 & 27 June 2013 with Faulkes Telescope North and again on 01 July 2013 with the Faulkes Telescope South at magnitude ~20. (follow-up observations have been obtained by T. Vorobjov on June 28, 2013 at Kitt Peak - MPC code 695).  It was already a couple of arcminutes off prediction. See our image below, stacking of 7x120 seconds exposures (click on it for a bigger version).

Below you can see a short animation showing the movement of the Herschel Space Observatory during our first observing session of June 26, 2013. Click on the thumbnail for a bigger version.

Using our data, Bill Gray calculated for Herschel a return to opposition on 2027 Oct 24 +/- 4 at about 0.055 AU, reaching mag 22.  Below you can see the new orbit (click on the image for a bigger version).

Credit: Bill Gray

by Ernesto Guido & Nick Howes

New Comet: C/2013 L2 (CATALINA)

Cbet nr. 3548, issued on 2013, June 09, announces the discovery of an apparently asteroidal object (discovery magnitude ~19.6)  by R. A. Kowalski on CCD images obtained with the Catalina Sky Survey 0.68-m Schmidt telescopeon June 02.  After posting on the Minor Planet Center's NEOCP webpage, this apparently asteroidal object as been found to show cometary features by by astrometric observers elsewhere. The new comet has been designated C/2013 L2 (CATALINA).

We performed follow-up measurements of this object, while it was still on the neocp. Stacking of 18 R-filtered exposures, 30-sec each, obtained remotely, from the Haleakala-Faulkes Telescope North on 2013, June 04.5, through a 2.0-m f/10.0 Ritchey-Chretien + CCD (operated by Las Cumbres Observatory Global Telescope Network), shows that this object is a comet: sharp central condensation, surrounded by a faint coma nearly 4" in diameter.

Below you can see our image. Click on it for a bigger version.

M.P.E.C. 2013-L41 assigns the following preliminary parabolic orbital elements to comet C/2013 L2: T 2012 Apr. 29.80; e= 1.0; Peri. = 359.60; q = 4.77;  Incl.= 106.44

by Ernesto Guido & Nick Howes

Possible Nova in Sco - PNV J17335943-3606216

Following the posting on the Central Bureau's Transient Object Confirmation Page about a possible Nova in Sco (TOCP Designation: PNV J17335943-3606216) we performed some follow-up of this object remotely through the 0.50-m f/6.8 astrograph + CCD + f/4.5 focal reducer of iTelescope network (MPC Code  Q62 - Siding Spring, AU).

On our images taken on June 03.7, 2013 we can confirm the presence of an optical counterpart with unfiltered CCD magnitude 11.5 at coordinates:

R.A. = 17 33 59.44, Decl.= -36 06 20.7

(equinox 2000.0; UCAC-3 catalogue reference stars).

Our annotated confirmation image (click on it for a bigger version). North is up, East is to the left:

 

An animation showing a comparison between our confirmation image and the archive POSS2/UKSTU plate (R Filter - 1996). Click on the thumbnail for a bigger version:

UPDATE - June 04, 2013

According to Cbet No. 3542, PNV J17335943-3606216 is now NOVA SCORPII 2013. This nova has been discovered by Koichi Nishiyama and Fujio Kabashima (Japan) on two 40-s unfiltered CCD frames (limiting magnitude 13.5) taken around June 3.6146 UT using a 105-mm f/4 camera lens (+ SBIG STL6303E camera). Spectra obtained by C. Buil (the spectrum shows a very reddened object, with an intense H-alpha emission line - equivalent width 2.9 nm; FWHM = 1200 km/s ), and independently by T. Bohlsen indicate a probable nova.

Credit: C. Buil, Castanet, France

by Ernesto Guido & Nick Howes

Comet C/2012 S1 (ISON) - Update May 20, 2013

Comet C/2012 S1 (ISON) was discovered on September 21, 2012 by Vitali Nevski and Artyom Novichonok on CCD images obtained with a 0.4-m f/3 Santel reflector of the International Scientific Optical Network (ISON) near Kislovodsk, Russia.

Comet C/2012 S1 (ISON) will get to within 0.012AU of the Sun (extremely close) at the end of  November 2013 and then to ~0.4AU from Earth at the end of December 2013! According to its orbit, this comet might become a naked-eye object in the period November 2013 - January 2014. And it might reach a negative magnitude at the end of November 2013. For more info about the discovery please see our previous post here. While here & here you can read our October 2012 updates about comet ISON.

Our Team working with a suite of Hubble sized telescopes in Australia, Hawaii and the Canary Islands is collaborating with a range of professional scientists in an attempt to get high spatial resolution data on comet C/2012 S1 (ISON). Supported by the Liverpool John Moores Astrophysics Research Institute and the Faulkes Telescope Project we have been imaging C/2012 S1 ISON since the day it was  discovered, being part of the discovery MPEC for the comet ourselves.
 

Our recent images taken with the 2m Telescopes on La Palma are being worked on as part of an ongoing collaboration which started with Comet 103P/Hartley 2 with Nalin Samarasinha, a Senior Scientist at the Planetary Science Institute (PSI) in Tucson, AZ, USA. Nalin, a specialist in comets at the Planetary Science Institute, has been looking at the detailed structure of the near nucleus coma of comet C/2012 S1 ISON using data we are delivering in to the PSI. (click on the images below to see a bigger version).

 

Most recently, Nalin had looked at image comparisons for our team’s dataset from May 02, 05, and 07 taken with the F10/2m telescope on La Palma, using an extremely sensitive camera, perfectly suited for detailed comet work.

The images shown here are 28x28 pixel crops of the inner region with the optocenter (assumed to be the nucleus) at the center. (click on it for a bigger version)

"This comparison shows that the sunward feature we suspected from images taken on 02/05/2013 is originating slightly north of west and then the position angle (PA) of the feature (measured from north through east) increases as one moves away from the optocenter" quotes Nalin. The exact PA of this feature is tricky to determine, as it will depend on how far away from the optocenter that you look at and when near the optocenter, PAs can be very uncertain. Nalin's interpretation is that the curvature of this feature is not due to any rotational effects but is due to radiation pressure pushing dust grains towards the tail. Ultimately, this feature merges in with the tail.

This amazing result from a ground based set of observations, is in close agreement with features detected by the Hubble Space Telescope in images taken in April of this year. It goes to show how valuable ground based observations can be.

Credit: NASA, ESA, and Z. Levay (STScI)

As the comet comes closer to the Earth the spatial resolution will improve, and we should get more detailed views on the coma structure. Ongoing collaborations with scientists with the amateur community have been discussed in many recently published papers, and  this is a prime example of one that is delivering valuable scientific data on a hugely interesting object.

by Nick Howes and Ernesto Guido

Close Approach of Asteroid (285263) 1998 QE2

Asteroid (285263) 1998 QE2 was discovered on Aug. 19, 1998, by the Massachusetts Institute of Technology Lincoln Near Earth Asteroid  Research (LINEAR) program.

1998 QE2 has an estimated size of 1.3 km - 2.9 km (based on the object's absolute magnitude H=16.6). It was observed by the Spitzer Space Telescope by Trilling et al. (2010), who estimated that it has a diameter of 2.7 km and a dark optical albedo of  0.06. This asteroid will have a close  approach with Earth at about 15.2 LD (Lunar Distances = ~384,000 kilometers) or 0.0392 AU (1 AU = ~150 million kilometers) at  2059 UT on 2013 May 31 and it will reach the peak magnitude ~10.8 on May 31 around 2300 UT.

(285263) 1998 QE2 will be a great Goldstone radar target May 30 through June 9. This is going to be one of the best radar targets of the year. Radar images from the Goldstone antenna could achieve resolutions as fine as 3.75 meters.

We performed some follow-up measurements of this object, from the Q62 iTelescope network (Siding Spring) on  2013, May 17.36, through a 0.50-m f/6.8 astrograph + CCD + f/4.5 focal reducer. Below you can see our image, stack of 15x10-second exposure, taken with the asteroid at magnitude ~14.5 and moving at ~3.13 "/min. At the moment of the close approach 1998 QE2 will move at ~23 "/min. Click on the image below to see a bigger version. North is up, East is to the left.

Below you can see a short animation showing the movement of 1998 QE2 (15x10-second exposures). Click on the thumbnail for a bigger version:

  
UPDATE - May 30, 2013

Radar images of asteroid 1998 QE2 obtained on the evening of May 29, 2013, by NASA scientists (led by scientist Marina Brozovic) using the 70-meter Deep Space Network antenna at Goldstone, Calif., show that it is a binary system.

Credit: NASA/JPL-Caltech/GSSR

According to the JPL press release: "Radar images suggest that the main body, or primary, is approximately 2.7 kilometers in diameter and has a rotation period of less than four hours. Also revealed in the radar imagery of 1998 QE2 are several dark surface features that suggest large concavities. The preliminary estimate for the size of the asteroid's satellite, or moon, is approximately 2,000 feet (600 meters) wide. The radar collage covers a little bit more than two hours. In the near-Earth population, about 16 percent of asteroids that are about 200 meters or larger are binary or triple systems."

UPDATE - May 31, 2013

We performed some follow-up measurements of this object on 2013, May 31.3 (few hours before its close approach), remotely from the iTelescope Observatory (H06 Mpc code), through a 0.25-m f/3.4 reflector + CCD. Below you can see our image, 1 single exposure of 180 seconds, taken with the asteroid at magnitude ~11.0 and moving at ~ 21.72 "/min. The asteroid is trailed in the image due to its fast speed. Click on the image below to see a bigger version. North is up, East is to the left.

Below you can see a short animation showing the movement of 1998 QE2 (20 consecutive 10-second exposures). North is up, East is to the left. Click on the thumbnail for a bigger version:

by Ernesto Guido & Nick Howes