Coordinated campaign:
OJ 287 during
a 3rd XMM-Newton observation in Nov.17, 2006
WEBT intensive-short campaign:
some days before, during and after the next granted XMM-Newton
observation (scheduled next Nov.17,
2006). |
Extended long-term monitoring campaign: long-term monitoring observations (Sept 2006 - June
2007, who is interested in). |
A third XMM-Newton
ESA satellite (here a XMM-Newton
fold-out picture) observation of OJ 287 is scheduled on
Nov.17, 2006 (about 48ksec, ~13h). A multiwavelength
WEBT
(mainly IR-radio-optical) intensive (all-night
observations) and
short campaign (some days before, during and after the XMM-Newton
pointing date) is invited.
Moreover this 2006-2007 season is an
important period to observe and monitor OJ 287 in the radio and
in the optical bands, because some models predict an outburst or dim
period in autumn 2006, and observers are invited to make observations
and monitoring when possible, starting from now (Sept.2006) and
during the next months. A photometry-polarimetry
monitoring of OJ 287 is already in ongoing, joint with dedicated
VLBA/VLBI observations. Intensive observations by the WEBT
and ENIGMA
member Institutes were already performed last
year during the previous 2 XMM-Netwon observations, joint with normal monitoring
observations during all the observing seasons. Regularly updated
optical light curve is available in the preview page of the optical polarization monitoring of OJ 287
The X-ray observations are requested to study the spectral and temporal
behaviour of OJ 287, on both short and long time scales, before
and during the
next probable outburst. X-ray data will provide
information on the high-energy spectral component (likely inverse
Compton emission), while radio-to-optical observations will map the
behaviour of the synchrotron emission component.
Target -PI |
RA |
Dec |
Position_Angle |
OJ 287 -S. Ciprini |
08:54:48.87 |
+20:06:30.6 |
103:35:04.8 |
XMM Obs_Duration |
XMM Obs: Start
Time |
XMM Obs: End
Time |
Satellite Revolution |
|
48300 sec |
2006 November
17 at 00:15:40 UT |
2006 November
17 at 13:40:40 UT |
1271 |
|
This XMM-Newton observation
was well performed without problems.
Our goal is to clarify the basic physics, and the
relevance of geometrical and energetic models in the
interpretation of
long/short-term variability, during both the quiescent and outburst
phases in this peculiar blazar.
|
|
Fig1:
Preliminary R-band optical light curve during the 2 XMM-Newton
observations and the related WEBT MW short campaigns (plus the
data coming from the extended monitoring in the season
2004-2005 and season 2005-2006). |
Fig2:
Preliminary summary of the whole multiband near-IR and optical
data obtained during the two observing seasons. |
Observations and data reduction:
|
Extended campaign: monitoring observations (Sept 2006 - June
2007, who is interested in)
We suggest that optical observers perform only few BVRI
photometric sequences, and mostly R-band monitoring when possible.
Small
telescopes (< 60cm) should perform R-band only
observations. Other band (for example U,
and J,H,K) are accepted. The source is visible at the end of
the night during fall. Radio-optical
monitoring observations of OJ 287 in the period are
accepted during all the current season (Sept.2006-June2007).
In this case also data files with final magnitudes of the
source only are accepted. It will be very useful if you can
add OJ 287 in your telescope observing schedules and
monitoring program during this season. In case of relevant
flaring/outbursting (when more intensive observations could be
useful), further updates will be sent. Your monitoring data
will be used in the ongoing photometry+polarimetry
monitoring programme.
|
|
WEBT intensive-short campaign
for some days before, during and after the 3rd XMM-Newton
observation on Nov.17, 2006:
We suggest that optical observers perform a BVRI sequence at the beginning and/or at the
end of the night, and a BR sequence during all
the available observing night-time hours. When a BR
sequence cannot be performed, we suggest to carry out observations
in the R-band only (this last choice is recommended to small
telescopes). Intensive observations are useful starting some days
before and ending some days after the satellite pointing date.
Optical data will be collected as instrumental magnitudes of the source and
comparison stars. The suggested data format
is in tables separated for each filter with rows as in the
example below:
JD-2453000 |
OJ 287 |
4 |
10 |
11 |
C1 |
C2 |
967.43408 |
14.362 0.005 |
14.382 0.008 |
14.370 0.030 |
14.461 0.060 |
14.622 0.060 |
14.703 0.070 |
where JD
must be geocentric at mid exposure with five decimal digits (or equivalent date +
UT with second precision e.g. 2006 10 01 00 00 01). Observers are requested to perform
bias/dark correction and flat-fielding on their frames, and to
obtain the instrumental mags with some procedure. Both aperture
photometry (for example using IRAF or CCDPHOT) or Gaussian fitting are
allowed. In the case of aperture photometry, we suggest that all
observers use the same parameters, i.e. 8, 13, and 18 arcsec for the
radii of the aperture and of the edges of the sky annulus. However,
the sky annulus radii can be seeing-dependent in order not to
contaminate the sky region with source flux. Here is the finding
chart and comparison photometric UBVRIJHK sequences for
OJ 287.
|
The variable brightness of OJ 287 is
about mag(R)= 16 - 13.5, and most telescopes should be able to
provide data a rather good S/N in exposures. Please remember that for variability analysis the precision on
the observations (frames) times is important as the photometric
precision (correct UT synchronization is possible looking for
example at the at USNO
clock especially during the core campaign). Other data and
information useful for the observations are online in the USNO
DataServices and Staralt
web pages.
Other observations related/connected to this campaign:
|
Swift
satellite ToO short (4 Ksec) observations performed on
Nov.16,17,18, 2006
|
|
MAGIC
ToO observations scheduled this week. MAGIC
ToO observations already executed simultaneously to the 3rd XMM
pointing (Nov.17, 2006).
|
|
Single dish 3mm polarimetric measurements
made with the IRAM 30m
mm-telescope on Nov.12,17,18,2006. VLBA
7mm and 1.2 cm radio-structure polarimetric-astrometric
observations succesfuly performed on Nov.16, 2006.
|
|
Effelsberg
100m radio observations scheduled.
|
OJ 287 is a pure BL Lac object, therefore optical polarization
measurements are important too. Observers having access to infrared telescope facilities, are invited to contribute
with infrared observations in the same way specified for the
optical strategy. Our
finding chart + magnitude table also contains the J, H,
K mag of comparison stars adopted.
During the campaign multiband radio flux
(priority) and polarization measurements are
important. The strategy is the same
mentioned above for the optical observers.
Contact
Data and information requests can be sent to all the following email addresses:
- S. Ciprini: stefano.ciprini<at>utu.fi
|