OJ 287 Project home

OJ 287 during two XMM observations in 2005 and
coordinated WEBT Campaign

A first XMM-Newton ESA satellite (here a XMM-Newton fold-out picture) observation of OJ 287 was performed in April 12, 2005, and a second observation performed in Nov. 03-04, 2005. A multiwavelength (mainly radio-optical) intensive and short observing campaign composed of two parts (around the satellite observation dates) was proposed to the WEBT international collaboration by Stefano Ciprini (Tuorla Obs. & ENIGMA Network). Intensive observations by the WEBT and ENIGMA member Institutes were performed in April and November 2005 during the two  XMM-Netwon pointings, while a normal monitoring by several observatories was still performed in the following weeks. The teams of the ENIGMA Network are contributing to both this short-term/intensive campaign and to the long-term monitoring of the source in the framework of the "OJ 287 2005-2008 Project".

The second XMM-Newton observation of about 51 ksec was scheduled during November 3-4, 2005. Intra-night observations by the WEBT (WEBT + ENIGMA members and who is interested in)  were requested during the days Nov. 2-3-4-5, 2005 (XMM satellite pointing: Nov. 3-4), and during the Effelsberg radio mini-campaign: Nov.8-9-10, 2005. Daily (one point per night) observations during the October-November months by the ENIGMA network teams are welcome. OJ 287 was optically bright (mag. R~13.6/13.4), during these observations.
    
Target RA Dec Position_Angle
OJ 287 08:54:48.87 +20:06:30.6 104:13:22.6
XMM Obs_Duration XMM Obs: Start Time XMM Obs: End Time Satellite Revolution IB
51000 sec 2005-11-03 at 20:59 UT 2005-11-04 at 11:09 UT 1081 E3

The XMM-Newton 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. Our goal is to clarify the basic physics, and the relevance of geometrical and energetic (SSC) models in the interpretation of long/short-term variability, during both the quiescent and outburst phases. We aim at comparing data and results on this probably quiescent phase of OJ 287 during 2005, with observations that we will propose also during the expected outburst phase, in order to search for correlations and precursory events. Dedicated bi-montly VLBA observations of this blazar in 5 bands from 2005 to 2008 are performing and scheduled. 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. These data will be compared also with the long term observations, to span a large range of variability timescales at different electromagnetic frequencies. intraday optical-radio observations will be very useful around the satellite pointing, in particular high-precision and high-sampling observations by Effelsberg 100m radio-observatory are recommended during the day of the XMM pointing (and possibly during the 4 days of the core campaign). OJ 287 was pointed in January also by the MAGIC gamma-ray Cherenkov telescope (total time 10h). One global 3mm-VLBI session will be performed after October 2005. MAGIC ToO observations are scheduled around the XMM pointing date.

 

Latest News:

NEW:  A new photometry-polarimetry programme is started (PI: J. Heidt & K. Nilsson)
NEW: A 3rd XMM-Newton observation (48ksec,
~13h) is scheduled in Nov.17, 2006. More information will be added later. (PI: S. Ciprini)
MAGIC ToO observations of OJ 287 performed in Nov.1-4 and Nov. 10-13 (PI: L. Lindfors).
Effelsberg 100m radio flux/polarization intraday observations of OJ 287 scheduled on Nov.8-9-10, 12h per day, (PI: L. Fuhrmann).

Part2 core campaign (intraday observations recommended):
November 2-3-4-5 (priority to November 3-4, XMM-Newton satellite pointing time) 
November 8-9-10 (epochs of the radio intraday observations "Effelsberg mini-campaign") 

XMM-Newton observations performed: second half of the pointing affected by high-background radiation (solar wind storm, earth proton belt radiation) and ~20% of time lost. Anyway the long pointing time allowed probably to have still good data. Simultaneous ground-based optical observations partially obstructed by bad weather. 

Part 2 (Oct. - Dec. 2005): Participating Observatories 

Institutes/Observatories and contact-person(s) - list updated by June 27, 2006:

Osaka University - Osaka, Japan (K. Torii)
Osaka Kyoiku University
- Kashiwara, Osaka, Japan (K. Sadakane, M. Kamata)
Sobaeksan KASI Optical Astronomy Observatory -  Sobaeksan, Korea (C.-U. Lee) 
Lulin Observatory - Lulin, Taiwan (W.-P. Chen)
Tsinghua University - Beijing, China (J. Li)
Xinglong Station of NAOC - Yanshan Mountains, China, (J.-H. Wu)
ARIES Sampurnanand Telescope  - Naini Tal, Uttaranchal, India (R. Sagar, G. Krishna)
Mount Maidanak Observatory, Ulugh Beg Astronomical Institute - Mount Maidanak, Uzbekistan (M. A. Ibrahimov)
Abastumani Astrophysical Observatory - Mt. Kanobil, Georgia, (O. Kurtanidze)
Crimean Astrophysical Observatory - Nauchny, Crimea, Ukraine (Y. Efimov, V. Larionov)
Çanakkale Onsekiz Mart University Observatory -  Çanakkale, Turkey (A. Erdem)
Saint Petersburg State University Observatory - St. Petersburg, Russia (V. M. Larionov)
Bulgaria National Astronomical Observatory - Rozhen, Bulgaria (E. Ovcharov, A. Kostov)
Jakokoski Observatory - Jakokoski, Finland (P. Pääkkönen)
Tuorla Observatory - Piikkio, Finland (L. Takalo, A. Sillanpää)
MonteBoo Observatory, Masaryk University - Brno, Czech Republic (F. Hroch)
Catania Observatory - Catania, Italy (A. Frasca)
Campo Imperatore Observatory - Assergi, L'Aquila, Italy (A. Arkharov)
Armenzano Observatory - Armenzano, Assisi, Italy (D. Carosati)
Porziano Observatory - Porziano, Assisi, Italy (D. Capezzali) 
Perugia Observatory - Perugia, Italy (G. Tosti, S. Ciprini)
Torino Observatory - Torino, Italy (C. Raiteri, M. Villata)
Heidelberg Observatory
- Heidelberg, Germany (L. Ostorero, D. Emmanoulopoulos)
Michael Adrian Observatory- Trebur, Germany (J . Ohlert)
KVA Telescope - La Palma, Canary Islands, Spain (L. Takalo, A. Sillanpää)
Nordic Optical Telescope - La Palma, Canary Islands, Spain (T. Pursimo)
INAOE Tonantzintla Observatory - Tonantzintla, Puebla, Mexico (O. Lopez-Cruz)
Mt. Lemmon KASI Observatory - Mount Lemmon, Arizona, USA (C.-U. Lee)
Ohio University MDM Observatory - Kitt Peak , Arizona, USA (M. Boettcher)
Kitt Peak SARA Observatory - Kitt Peak, Arizona, USA (J. Webb)
Tenagra Observatories - Sonoran desert, Arizona, USA (A. Sadun)
National Astronomical Observatory of San Pedro Mártir - Baja California Peninsula, Mexico  (E. Benitez,  D. Dultzin-Hacyan.)
Coyote Hill Observatory - Wilton, Sacramento, California, USA (C. Pullen)

RATAN-600 (Special Astrophysical Observatory) (576 m) - Zelenchukskaya, Russia (Y. Kovalev)
RT-22 Crimean Astrophysical Observatory
(22m ) -  Simeiz, Crimea, Ukraine (A. Volvach)
Metsähovi Radio Telescope
(14 m) - Metsähovi, Finland (M. Tornikoski, A. Lahteenmaki)
Noto Radio Observatory (32m) - Noto, Siracusa, Italy (P. Leto, C. Raiteri)
Effelsberg Radio Telescope
(100 m) - Effelsberg, Germany (T. Krichbaum, L. Fuhrmann)
IRAM Millimeter Telescope (30 m) - Pico Veleta, Spain (T. Krichbaum, H. Ungerechts)
University of Michigan Radio Astronomy Observatory (UMRAO) (26 m) - Dexter, Michigan, USA (M. Aller)

 

Part 1 (April-May  2005): Participating Observatories 

Institutes/Observatories and contact-person(s) - list updated by June 26, 2005:

Osaka Kyoiku University Observatory - Kashiwara, Osaka, Japan (K. Sadakane) 
Lulin Observatory - Lulin, Taiwan (W. P. Chen
Xinglong Station of NAOC - Yanshan Mountains, China, (J.-H. Wu)
ARIES Sampurnanand Telescope  - Naini Tal, Uttaranchal, India (R. Sagar, G. Krishna)
Abastumani Astrophysical Observatory - Mt. Kanobil, Georgia, (O. Kurtanidze)
Crimean Astrophysical Observatory - Nauchny, Crimea, Ukraine (Y. Efimov, V. Larionov)
Çanakkale Onsekiz Mart University ObservatoryÇanakkale, Turkey (A. Erdem)
Jakokoski Observatory - Jakokoski, Finland (P. Pääkkönen)
Nyrölä Observatory - Nyrölä, Finland (A. Oksanen)
Tuorla Observatory - Piikkio, Finland (L. Takalo, A. Sillanpää)
Catania Observatory - Catania, Italy (A. Frasca)
Campo Imperatore Observatory - L'Aquila, Italy (V. Larionov)
Armenzano Observatory - Armenzano, Assisi, Italy (D. Carosati)
Perugia Observatory - Perugia, Italy (G. Tosti, S. Ciprini)
Torino Observatory - Torino, Italy (C. Raiteri, M. Villata)
Heidelberg Observatory
- Heidelberg, Germany (J. Heidt)
Michael Adrian Observatory- Trebur, Germany (J . Ohlert)
Agrupacio Astronomica de Sabadell - Sabadell, Spain (J. A. Ros)
KVA Telescope - La Palma, Canary Islands, Spain (L. Takalo, A. Sillanpää)
Nordic Optical Telescope - La Palma, Canary Islands, Spain (T. Pursimo)
Mt. Lemmon KASI Observatory - Mount Lemmon, Arizona, USA (C.-U. Lee)
Kitt Peak SARA Observatory - Kitt Peak, Arizona, USA (J. Webb)
Tenagra Observatories - Sonoran desert, Arizona, USA (A. Sadun)
Coyote Hill Observatory - Wilton, Sacramento, California, USA (C. Pullen)

RATAN-600 (Special Astrophysical Observatory) (576 m) - Zelenchukskaya, Russia (Y. Kovalev)
Metsähovi Radio Telescope
(14 m) - Metsähovi, Finland (M. Tornikoski, A. Lahteenmaki)
Noto Radio Observatory (32m) - Noto, Siracusa, Italy (P. Leto, C. Raiteri)
Effelsberg Radio Telescope
(100 m) - Effelsberg, Germany (T. Krichbaum, L. Fuhrmann)
IRAM Millimeter Telescope (30 m) - Pico Veleta, Spain (T. Krichbaum, H. Ungerechts)
University of Michigan Radio Astronomy Observatory (UMRAO) (26 m) - Dexter, Michigan, USA (M. Aller)
NRAO Very Long Baseline Array (VLBA) - USA (I. Agudo)

NEW: Preliminary R-band optical light curve during the XMM-Newton and WEBT MW campaign (plus the extended 2005-06 campaign).  NEW: Preliminary summary of near-IR and multiband optical light curves during the campaign. 

   
November 3-4, 2005
: XMM-Newton observations performed: second half of the pointing affected by high-background radiation. Simultaneous ground-based optical observations partially obstructed by bad weather. 
   
April 12, 2005: XMM observations affected by high radiation background and partially stopped due to bad space weather (a solar flare occurred during the pointing and only about 4-hours of XMM observing time were possible). Anyway OJ 287 was detected (here the first raw-image of OJ 287 in X-ray by XMM) and the extra-time granted will be added to the next pointing in November. Optical ground-based observations obstructed by bad weather in Europe in that day. Effelsberg 100-m radio-observations well carried out.
   
4-days core and April campaign: rather good optical observations in the other days of the WEBT campaign. Some radio, optical-polarization and near-IR data also available. VLBA & 3mm-VLBI observations on 2 and 17 April. Good optical monitoring during April by several observatories.

   

Observing Strategy 

Optical observations and data reduction:
  
Extended campaign: the new season (October 2005 - April 2006) (ENIGMA Network teams only and who is interested in).
We suggest that optical observers perform BVRI (Johnson's B,V and Cousins' R,I, if possible) sequences when possible with a R-band additional sequence. For small telescopes (< 60cm) we suggest to perform R-band only sequences. Other band (for example U, and J,H,K) are accepted. The source in October-November is visible at the end of the night for Europe observers.

WEBT campaign (part1 and part2): 
We suggest that optical observers perform a  BVRI (Johnson's B,V and Cousins' R,I, if possible; other filters are also accepted) 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).  This allows us to get simultaneous light curves in B and R bands for optical spectral variability studies too. Then a 4-days period will allow to search for possibly short lags between X-ray and radio-optical emission.
The brightness of OJ 287 (out of the cyclical outbursts phases) 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.
      

Data will be collected as instrumental magnitudes of the source and reference stars, in order to apply the same analysis and calibration procedures to all datasets. The suggested data format is in tables separated for each filter with rows as in the example below: 

JD-2452000 OJ 287 4 10 11 C1 C2
1067.43408 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 (or equivalent date + UT) must be geocentric at mid exposure. Times are requested with second precision (e.g. 2003 10 01 00 00 01, or the preferred corresponding JD - 2452000 = 913.50001 with five decimal digits); mags and errors should have three decimal digits. 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 (possibly 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.

Data format recommendation: we strongly encourage the observers to provide data in the exact format specified above. The adjustment of numerous different formats is a time-consuming work, it can induce errors and it delays the analysis and publication of results. 
       
OJ 287 is a pure BL Lac object, therefore optical polarization measurements are very important too.
    

   
Near-IR Observations
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.     
    

Radio Observations

During the campaign multiband radio flux (priority) and polarization measurements are important. The strategy is the same mentioned above for the optical observers.

Contacts

All observers interested in participating in this campaign are invited to send messages and data to the following 3 addresses (on the same email):
- this Campaign Manager (S. Ciprini: stefano.ciprini<at>utu.fi)
- the WEBT President (M. Villata: villata<at>to.astro.it)
- one of the OJ 287 2005-2008 Project Managers (L. Takalo: leo.takalo<at>utu.fi)

 

 
LLLsddd4etLast update: August 21, 2006, S. Ciprini