Astronomy and Astrophysics – Astrophysics
Scientific paper
1999-10-27
Astronomy and Astrophysics
Astrophysics
AASTeX 4.0 preprint style, 21 pages, 8 EPS figures
Scientific paper
10.1086/309305
We have continued our effort to re-reduce archival Q0957+561 brightness monitoring data and present results for 1629 R-band images using the methods for galaxy subtraction and seeing correction reported previously. The new dataset comes from 4 observing runs, several nights apiece, with sampling of typically 5 minutes, which allows the first measurement of the structure function for variations in the R-band from timescales of hours to years. Comparison of our reductions to previous reductions of the same data, and to r-band photometry produced at Apache Point Observatory shows good overall agreement. Two of the data runs, separated by 417 days, permit a sharpened value for the time delay of 417.4 days, valid only if the time delay is close to the now-fashionable 417-day value; our data do not constrain a delay if it is more than three days from this 417-day estimate. Our present results show no unambiguous signature of the daily microlensing, though a suggestive feature is found in the data. Both time delay measurement and microlensing searches suffer from from the lack of sampling at half-day offsets, inevitable at a single observatory, hence the need for round-the-clock monitoring with participation by multiple observatories.
Colley Wesley N.
Schild Rudolph E.
No associations
LandOfFree
Hourly Variability in Q0957+561 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Hourly Variability in Q0957+561, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Hourly Variability in Q0957+561 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-608839