OJ 287 Project home

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.

OJ 287 Project homepage
Finding chart and comparison photometric UBVRIJHK sequences for OJ 287
The previous two XMM-Newton observations in 2005 & WEBT-ENIGMA multiwavelength campaign 
Long term photometry+polarimetry monitoring programme
- NED database information on OJ 287
OJ 287 bibliography/information: - by ADS-NASA   - by NED   - by CDS-Simbad   

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.


Data and information requests can be sent to all the following email addresses: 

- S. Ciprini: stefano.ciprini<at>utu.fi



LLLsddd4etLast update: Nov. 22, 2006, S. Ciprini