Tuesday, December 10, 2013

Close Approach of Asteroid 2013 XY8

M.P.E.C. 2013-X44, issued on 2013, December 08, reports the discovery of the asteroid 2013 XY8 (discovery magnitude 17.7) by Catalina Sky Survey (MPC code 703 ) on images taken on December 07.1 with a 0.68-m Schmidt + CCD.

2013 XY8 has an estimated size of 31 m - 68 m (based on the object's absolute magnitude H=24.7) and it will have a close approach with Earth at about 2 LD (Lunar Distances = ~384,000 kilometers) or 0.0051 AU (1 AU = ~150 million kilometers) at 1117 UT on 2013, December 11. This asteroid will reach the peak magnitude ~14.4 between December 10 & 11.

We performed some follow-up measurements of this object on 2013, December 10.6, remotely from the Faulkes Telescope South (MPC code E10), through a 2.0-m f/10.0 Ritchey-Chretien + CCD (Faulkes Telescope is operated by Las Cumbres Observatory Global Telescope Network).

Below you can see our image taken with the asteroid at magnitude ~15 and moving at ~78.0 "/min. At the moment of the close approach 2013 XY8 will move at ~151"/min. Click on the image below to see a bigger version. North is up, East is to the left (the asteroid is trailed in the image due to its fast speed).

Below you can see a short animation showing the movement of 2013 XY8 (four consecutive 30-second exposure). Click here or on the thumbnail for a bigger version:

Animation of Close Approach of Asteroid 2013 XY8 - 2013, December 10.6 photo animation_zps3b70bd1c.gif
by Ernesto Guido, Nick Howes & Martino Nicolini

Tuesday, December 3, 2013

Possible Bright Nova in Centaurus

Following the posting on the Central Bureau's Transient Object Confirmation Page about a possible Nova in Cen (TOCP Designation: PNV J13544700-5909080) we performed some follow-up of this object remotely through the 0.50-m f/6.8 astrograph + CCD + focal reducer of iTelescope network (MPC Code  Q62 - Siding Spring, AU).

On our images taken on December 03.68, 2013 we can confirm the presence of an optical counterpart with unfiltered CCD magnitude  ~5.0 at coordinates:

R.A. = 13 54 45.22, Decl.= -59 09 04.5 (equinox 2000.0; UCAC-3 catalogue reference stars).

According to Vizier the nearest star (located at 1.538 arcsecond from the transient) to this position in the USNO-B1.0 catalogue is:

USNO-B1.0  0308-0442031   (J2000) 13 54 45.374 -59 09 03.52    mag. B2=15.52 R2 =15.12

Our confirmation image (click on it for a bigger version):

Below an animation showing a comparison between our confirmation image and the archive POSS2/UKSTU plate (R Filter - 1999). Click here or on the thumbnail below for a bigger version. 


UPDATE - December 04, 2013

According to CBET No. 3732, PNV J13544700-5909080 is now NOVA CENTAURI 2013. This nova has been discovered by John Seach (Chatsworth Island, NSW, Australia) in six CCD images obtained with a digital SLR camera (+ 50-mm-f.l. f/1.0 lens; limiting mag 11) taken on Dec. 2.692 UT. Low-resolution spectrograms reported independently by M. Locke and R. Kaufman show strong H_alpha and H_beta emission indicative of a nova.

by Ernesto Guido, Nick Howes & Martino Nicolini