scholarly journals Long-term and intra-day variability of BL Lacertae since the last great outburst

2006 ◽  
Vol 2 (S238) ◽  
pp. 419-420 ◽  
Author(s):  
Maria G. Nikolashvili ◽  
Omar M. Kurtanidze
Keyword(s):  
Ccd Camera ◽  
Active Phase ◽  
Optical Variability ◽  
Optical Photometry ◽  
Bl Lacertae ◽  
Maximum Variation

AbstractWe present the results of optical photometry of BL Lacertae carried out using ST-6 CCD camera attached to the Newtonian focus of the 70 cm meniscus telescope of Abastumani Observatory. On the basis of observations conducted since August 1997 during more than 550 nights about 17000 frames were collected. They have been reduced using Daophot II.It has been shown that optical variability of BL Lacertae is very complex. The maximum variation was observed at long-term scale and is equal to equals to 3.0 mag (rms=0.03) in B band, while the variation in V and R bands are within 2.71 mag (0.02) and 2.53 mag (0.01), respectively. This means that variations are larger at shorter wavelength or the object become bluer in the active phase. It were also demonstrated that BL Lacertae shows intra-day variability within 0.30 mag (0.02), while intra-hour variability within 0.10 mag (0.01) magnitudes.

scholarly journals The Long-Term Optical Variability of the BL Lacertae Object S5 0716+714: Evidence for a Precessing Jet

2005 ◽  
Vol 130 (4) ◽  
pp. 1466-1471 ◽  
Author(s):  
R. Nesci ◽  
E. Massaro ◽  
C. Rossi ◽  
S. Sclavi ◽  
M. Maesano ◽  
...  
Keyword(s):  
Optical Variability ◽  
Bl Lacertae

Charge coupled devices (CCD) photometry and long-term optical variability of gamma-ray-loud BL Lacertae object Mkn 421

2006 ◽  
Vol 15 (9) ◽  
pp. 2185-2192 ◽  
Author(s):  
Zhang Xiong ◽  
Zheng Yong-Gang ◽  
Zhang Hao-Jing ◽  
Hu Shao-Ming ◽  
Xie Zhao-Hua
Keyword(s):  
Gamma Ray ◽  
Optical Variability ◽  
Ccd Photometry ◽  
Bl Lacertae ◽  
Charge Coupled Devices

Brief summary of Kleť photographic search programme for minor planets

1999 ◽  
Vol 173 ◽  
pp. 189-192
Author(s):  
J. Tichá ◽  
M. Tichý ◽  
Z. Moravec
Keyword(s):  
Ccd Camera ◽  
Minor Planet ◽  
Minor Planets ◽  
Main Belt

AbstractA long-term photographic search programme for minor planets was begun at the Kleť Observatory at the end of seventies using a 0.63-m Maksutov telescope, but with insufficient respect for long-arc follow-up astrometry. More than two thousand provisional designations were given to new Kleť discoveries. Since 1993 targeted follow-up astrometry of Kleť candidates has been performed with a 0.57-m reflector equipped with a CCD camera, and reliable orbits for many previous Kleť discoveries have been determined. The photographic programme results in more than 350 numbered minor planets credited to Kleť, one of the world's most prolific discovery sites. Nearly 50 per cent of them were numbered as a consequence of CCD follow-up observations since 1994.This brief summary describes the results of this Kleť photographic minor planet survey between 1977 and 1996. The majority of the Kleť photographic discoveries are main belt asteroids, but two Amor type asteroids and one Trojan have been found.

scholarly journals The significance of metalloproteinase 3 (MMP-3), chemokine CXC ligand 13 (CXCL-13) and complement component C5a in different stages of ANCA associated vasculitis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Aleksandra Rymarz ◽  
Magdalena Mosakowska ◽  
Stanisław Niemczyk
Keyword(s):  
Characteristic Curve ◽  
Active Phase ◽  
Complement Component ◽  
Active Group ◽  
Control Group ◽  
Creatinine Concentration ◽  
Anca Associated Vasculitis ◽  
Good Ability ◽  
Potential Marker

AbstractThe aim of the study was to evaluate the significance of metalloproteinase 3 (MMP-3), chemokine CXC ligand 13 (CXCL-13) and complement component 5a (C5a) in different stages of ANCA associated vasculitis (AAV). 89 adults were included into the study. 28 patients with active AAV (Birmingham Vasculitis Activity Score, BVAS > 3) formed the Active Group. 24 individuals who were in remission after 6 months of induction therapy formed the Short R Group, while 34 patients with longitudinal remission formed the Long R Group. 28 patients without autoimmune diseases similar in terms of age, gender and stage of kidney disease formed the Control Group. Receiver operating characteristic curve analysis (ROC) was used to evaluate MMP-3, CXCL-13 and C5a as markers of the different phases of vasculitis. In ROC analysis, MMP-3, CXCL-13 and C5a presented a good ability in distinguishing active vasculitis (Active Group) from the Control Group (AUC > 0.8), whereas only CXCL-13 displayed potential ability in distinguishing active vasculitis (Active Group) from long term remission (Long R Group, AUC = 0.683). MMP-3 significantly and positively correlated with serum creatinine concentration (r = 0.51, p = 0.011; r = 0.44, p = 0.009; r =  −0.66, p < 0.001) and negatively with eGFR (r =  −0.5, p = 0.012; r =  −0.35, p = 0.039; r =  −0.63, p < 0.001) in the Short R, Long R and Control Groups. MMP-3, CXCL-13, C5a can be potential markers in differentiating an active phase of vasculitis from other pathologies. However they can be treated as complementary to the well-known markers. CXCL-13 seems to be a potential marker in distinguishing active vasculitis from long term remission. MMP-3 level can be related to kidney function expressed by eGFR, therefore its elevation should be interpreted with caution in patients with kidney failure.

scholarly journals Multiband optical variability studies of BL Lacertae

2015 ◽  
Vol 450 (1) ◽  
pp. 541-551 ◽  
Author(s):  
Aditi Agarwal ◽  
Alok C. Gupta
Keyword(s):  
Optical Variability ◽  
Bl Lacertae

CCD Photometry and Optical Variability of Gamma-Ray-loud BL Lacertae Object OJ 287 in a Low, Fainter State

2007 ◽  
Vol 133 (5) ◽  
pp. 1995-2000 ◽  
Author(s):  
X. Zhang ◽  
G. Zhao ◽  
Y. G. Zheng ◽  
L. Ma ◽  
Z. H. Xie ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Optical Variability ◽  
Ccd Photometry ◽  
Bl Lacertae

VERITAS OBSERVATIONS OF RELATIVISTIC OUTFLOWS IN LOW- AND INTERMEDIATE-FREQUENCY-PEAKED BL LAC OBJECTS

2014 ◽  
Vol 28 ◽  
pp. 1460178
Author(s):  
◽  
HEIKE PROKOPH
Keyword(s):  
Gamma Ray ◽  
Intermediate Frequency ◽  
Bl Lac Objects ◽  
Bl Lacertae ◽  
Bl Lac ◽  
Bl Lacs ◽  
Gamma Ray Telescopes ◽  
Very High

The majority of blazars detected at very high energies (VHE; E > 100 GeV) are high-frequency-peaked BL Lac objects (HBLs). Low- and intermediate-frequency-peaked BL Lacs (LBLs/IBLs with synchrotron-peak frequencies in the infrared and optical regime) are generally more powerful, more luminous, and have a richer jet environment than HBLs. However, only a handful of these IBL and LBLs have been detected by ground-based gamma-ray telescopes, typically during high-flux states. The VERITAS array has been monitoring five known VHE LBLs/IBLs since 2009: 3C 66A, W Comae, PKS 1424+240, S5 0716+714 and BL Lacertae, with typical exposures of 5-10 hours per year. The results of these long-term observations are presented, including a bright, subhour-scale VHE flare of BL Lacertae in June 2011, the first low-state detections of 3C 66A and W Comae, and the detection and characterization of the IBL B2 1215+30.

scholarly journals The variability and periods in the BL Lac AO 0235+164

2014 ◽  
Vol 10 (S313) ◽  
pp. 81-82
Author(s):  
J. H. Fan ◽  
O. Kurtanidze ◽  
X. Liu ◽  
Y. Liu ◽  
H. T. Wang ◽  
...  
Keyword(s):  
Ccd Camera ◽  
Monitoring Programme ◽  
Bl Lacertae Objects ◽  
Monitoring Period ◽  
Bl Lacertae ◽  
Periodicity Analysis ◽  
Photometric Observations ◽  
Bl Lac ◽  
Primary Focus ◽  
Electro Magnetic

AbstractVariability is one of the extreme observational properties of BL Lacertae objects. AO 0235+164 is a well studied BL Lac through the whole electro-magnetic wavebands, it is violently variable in the optical bands. In the present work, we show its optical R band photometric observations carried out during the period of Nov. 2006 to Dec. 2012 using the Ap6E CCD camera attached to the primary focus of the 70 cm meniscus telescope at Abastumani Observatory, Georgia. It shows a large variation of ΔR = 4.88 mag (14.20 - 19.08 mag) during our monitoring period. When periodicity analysis methods are adopted to its R observations from our Abastumani monitoring programme and those in the literature, the signs of some periods, P1 = 8.26 yr, P2 = 0.55 yr, P3 = 0.85 yr, P4 = 1.99 yr are found.

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