We carried out a comparison of the signals seen in contemporaneous BiSON and GOLF data sets. Both instruments perform Doppler shift velocity measurements in integrated sunlight, although BiSON perform measurements from the two wings of potassium absorption line and GOLF from one wing of the NaD1 line. Discrepancies between the two datasets have

Not Available

We have been monitoring the optical counterpart of the TeV emitting binary LSI +61 303 (V615 Cas) since November 2005 with the Faulkes Telescope North (on Haleakala, Maui), as part of a program to monitor long-term variability in X-ray binaries. Prompted by the recent SGR-like burst observed from a source in the region of LSI +61 303 (GCN 8209

We present the discovery of optical/X-ray flux correlations on rapid time-scales in the low/hard state of the Galactic black hole GX339-4. The source had recently emerged from outburst and was associated with a relatively faint counterpart with mag V ~ 17. The optical [Very Large Telescope (VLT)/ULTRACAM] and X-ray (Rossi X-ray Timing Explorer)

We studied the fraction and properties of bars in a sample of about 3000 galaxies extracted from SDSS-DR5. This represents a volume limited sample with galaxies located between redshift 0.01 -20, and inclination i 60°. Interacting galaxies were excluded from the sample. The fraction of barred galaxies in our sample is 45%. We found that 32% of S0s

We analyze the timing of photons observed by the MAGIC telescope during a flare of the active galactic nucleus Mkn 501 for a possible correlation with energy, as suggested by some models of quantum gravity (QG), which predict a vacuum refractive index ≃1+E, n=1,2. Parametrizing the delay between γ-rays of different energies as Δt=±τE or Δt=±τE, we