The new monthly MPC circular released.

ISON-NM statistic for the previous month (July 20 – August 21):

Number of measurements: 7777

Measured objects: 1861

Discovered objects: 7 (2010 PK26*; 2010 PX58; 2010 PY58; 2010 PY74, 2010 PR75*; 2010 PS75; 2010 PT75)

Sky coverage: 880 sq. degrees

Observing nights**: 19

* – interested object

** – include partial nights

TOP 20 number of observations by 2010 year:

 Year   Code    # Obs  # Num MPs # Unnum MPs   #Comets    #Sats
 2010   C51   3752281     98846     53961        94         6
 2010   704   1000204     79801      5393        58         1
 2010   G96    745875     78185     30958        40         0
 2010   703    591011     62291      7456        44         0
 2010   691    370928     44816     18049        29         3
 2010   F51    251195     62189      9834         0         0
 2010   J75    180726     32512      2126         8         0
 2010   E12    130160     18732      1393        18         2
 2010   D29     91013     18147      1378         3         1
 2010   291     33521      5397      2700        23         1
 2010   106     25615      5548       228         8         1
 2010   G92     16285      3627       271         4         0
 2010   H15     10764      2348       134        19         0 
 2010   683      9103      1455        23         4         0
 2010   A77      8803      1555       311        79         0
 2010   H21      6673       109       763        25         0
 2010   A50      5497      1470       251         2         0
 2010   926      5327       264       801        21         0
 2010   J04      5216      1142       288         2         0
 2010   H10      3878       396       176        67         0

Just look on this wonderful and pictorial video.

August 20th and 21st we continued our observations of the unusual gamma ray burster GRB100814A. After a lengthy “plateau” at magnitude 19.5-20, the object began to decrease in brightness. On August 20th it had reached mag. 21.66, and within a day was at mag. 22.5. Today’s observations were probably our final ones of this enigmatic object. Tomorrow its brightness may reach mag. 23.5-24 which is not reachable by our telescope. It is also interesting that GRB100814A is the first gamma ray burster whose afterglow was observed over a period of three nights at the observatory ISON-NM! At the moment scientists have not yet put forth a hypothesis about the nature of this long-duration gamma ray burster. Most probably it is not an explosion of a very distant so-called “hypernova”. The duration of the explosions may be connected to repeat episodes of activity or to geometric effects – we are seeing a jet from a substantial angle.

It is interesting that GRB100814A on August 18th with the aid of the high sensitivity radio telescope EVLA (Expanded Very Large Array) was also found to have an radio afterglow at wavelengths of 4.5 and 7.9 gigahertz. Radio components of gamma ray bursters with distances exceeding z=0.5 are seldom observed . I remind the reader that the distance to GRB100814A is calculated to be z=1.44 (9.3 billion light years).

TITLE:   GCN CIRCULAR
NUMBER:  11133
SUBJECT: GRB 100814A: ISON-NM optical observations
DATE:    10/08/22 07:30:05 GMT
FROM:    Leonid Elenin at ISON

L. Elenin, I. Molotov (ISON), A. Volnova (SAI MSU), A. Pozanenko (IKI)
report on behalf of larger
GRB  follow-up collaboration:

We continue observation of the Swift GRB 100814A (Beardmore et al. GCN
11087) with 0.45-m telescope of ISON-NM observatory on Aug. 20 (UT)
08:42:06 – 09:33:14 and Aug. 21 (UT) 09:45:22 – 11:04:41.

The afterglow (Schaefer et al. GCN  11086; Beardmore et al. GCN  11087)  is
well detected on stacked images for both epochs. Preliminary photometry of
unfiltered image against USNO-B1.0 star 0720-0016107, assuming R=19.73  is
following:

T-T0,  filter, exposure,  OT
(day)

6.2205    W     300×10    21.66  +/- 0.23
7.2734    W     300×15    22.50  +/- 0.30

The photometry errors are statistical only.

The images of GRB100814A is available at:

http://spaceobs.org/images/GRB1000814A-3epoch.jpg