DQ Her
Observations
DQ Her has been observed three times (With plans to do 2 more observations) from the Utah Desert Remote Observatory (UDRO) using iTelescope on 6/9/23, 6/12/23, and 6/13/23, producing 97 images. These images were taken with a V filter and an exposure time of 120 seconds. We captured these images between 1 A.M. and 4 A.M. with its peak at around 2 A.M. Using Astro ImageJ, we measured the magnitude of the light and then used Vstar to analyze the frequency, power, and period. After analyzing these images we discovered that DQ Her has substantial dips in its 4-hour 39-minute period. This matches what NASA says about DQ Her whose oscillation is proven because the white dwarf eclipses during its period.
Light Curve
Light Curve for the 23 images collected on 6/9/2023 with an exposure time of 120 seconds
6/9/2023
Light Curve for the 35 images collected on 6/12/2023 with an exposure time of 120 seconds
6/12/2023
Light Curve for the 39 images collected on 6/13/2023 with an exposure time of 120 seconds
6/13/2023
Period Analysis: Power vs Frequency
Power vs Frequency graph made from 23 images collected on 6/9/2023 with an exposure time of 120 seconds
6/9/2023
Power vs Frequency graph made from 35 images collected on 6/12/2023 with an exposure time of 120 seconds
6/12/2023
Power vs Frequency graph made from 39 images collected on 6/13/2023 with an exposure time of 120 seconds
6/13/2023
Period Analysis: Power vs Period
Power vs Period graph made from 23 images collected on 6/9/2023 with an exposure time of 120 seconds. The period is 0.002 to 0.14
6/9/2023
Power vs Period graph made from 35 images collected on 6/12/2023 with an exposure time of 120 seconds. The period is 0.002 to 0.5
6/12/2023
Power vs Period graph made from 35 images collected on 6/12/2023 with an exposure time of 120 seconds. The period is 0.002 to 0.4
6/13/2023
Phase Plots
Phase Plot created from the 23 images collected on 6/9/2023 with an exposure time of 120 seconds
6/9/2023
Phase Plot created from the 35 images collected on 6/12/2023 with an exposure time of 120 seconds
6/12/2023
Phase Plot created from the 39 images collected on 6/13/2023 with an exposure time of 120 seconds
6/13/2023
Combined Data
Sum: DQ Her's light curves
The Light Curve chart of all 97 images. These images were taken before we subtracted the difference between the three sets of images.
Sum: Power vs Frequency
This is the power vs frequency graph of all 97 images. We took this period analysis after we subtracted the difference in the average brightness of the three sets of images.
Sum: Power vs Period
This is the power vs frequency graph of all 97 images. We took this period analysis after we subtracted the difference in the average brightness of the three sets of images. The period is from .2 to 1.
Sum: Phase Plot
This is the phase plot of all 97 images. We made this phase plot after we subtracted the difference in the average brightness of the three sets of images.
Varying Oscillations: 71 or 142?
There has long been a discussion about whether the oscillation time for DQ Her is 71 or 142 seconds. Since its discovery in 1934, DQ Her has been thought to have an oscillation of 71.06 seconds. Research later on done by Zhang et al. (1995) has strong evidence proving the legitimacy of Nelson (1975) claim stating that the oscillation period is 142 seconds. Even later Butters et al. (2009) found evidence that supports the idea of a 142-second oscillation. During our research, we found stronger evidence supporting a 142-second oscillation over a 71-second oscillation.
Period Analysis: 71 or 142?
An oscillation that takes 71 seconds is 0.00082251832 days and a 142-second oscillation is 0.00164503646 days. The periods 0.0012 and 0.0024 have much higher power levels than the 0.0008 period. It's difficult because there is a period more accurate to the 71-second oscillation, but it is very weak. On the other hand, the two periods surrounding the 142-second oscillation are less accurate but have significantly higher power.
Additional Data
This data was collected after combining the original data between 06/09 and 06/14. These images were captured on 06/29/2023.