Welcome to KSE Observatory

Recent activity at KSE Observatory
--Be sure to check the Archive section for past activity--

November 16, 2016: Rapid optical variability of a magnetic white dwarf.

FO Aquarius is a magnetic white dwarf classified as an "intermediate polar" and is the object of interest to astronomer Dr. Colin Littlefield. using the XMM-Newton X-Ray telescope. The AAVSO issued a request for optical observations to assist Dr. Littlefield in his work to further understand the characteristics of this unusual stellar remnant and this class of objects in general. Fortunately, the sky was clear over KSE Observatory during the scheduled XMM-Newton observations, although the bright "Super Moon" reduced the signal to noise ratio somewhat in the CCD photometry of this 14th magnitude object.

The AAVSO Special Notice #425 reads:
Further to AAVSO Alert Notice 545, time series observations of the intermediate polar cataclysmic variable FO Aqr are requested to provide simultaneous coverage of XMM-Newton observations scheduled for 2016 November 13 19:43 UTC to November 14 8:13 UTC.

Dr. Colin Littlefield (University of Notre Dame) writes on behalf of his colleagues and himself: "We'd be grateful for simultaneous time-series photometry by AAVSO observers in support of these observations. Our primary objective for the AAVSO observations is to see how FO Aqr's X-ray behavior correlates with its optical variations.

"...FO Aqr is the subject of an ongoing AAVSO campaign to monitor its recovery from the first-ever faint state in its observational history. A number of AAVSO observers were co-authors on our first paper about FO Aqr's faint state [Littlefield et al., 2016, accepted for publication in ApJ; https://arxiv.org/abs/1609.01026].

A total of 90 images were taken at approximately 90 second intervals (60 second exposure + 30 second download) over the course of 2.25 hours until the target was about 30 degrees above the Western horizon. The images were taken through a photometric V filter, reduced and processed using AIP4Win 2.4.2, and the resulting photometric data uploaded to the AAVSO. The "Quick Look" plot produced by AIP4Win is shown below. The comparison and check star difference (C2-C1) is fairly flat over the 90 images which indicates that the variability in the target star is due to the object itself rather than the telescope, camera, seeing, etc.

Click on the image to enlarge.

Here's an image from the AAVSO Light Curve Generator which shows the KSE Observatory data (EEY) as blue squares in the light curve of FO Aqr on the night of Nov. 14th (UT). The KSE Observatory data generally fits well in the overall light curve and fills some observational gaps.

Click on the image to enlarge:

December 20, 2015: No Alien signals from KIC 8462852!

Within the field of view of the Kepler Space Telescope, a star designated as KIC 8462852 was in the news last November because of it's short, unusual, and large amplitude dimming periods. Discovered by volunteers combing through the data, the light from this star dimmed up to 20% and appeared to be random in timing and amplitude. It quickly made the news on suggestions that the dimming of the star's light was the result of an alien civilization's activity. Even the SETI team became involved and they searched for radio and optical signals which may have been sent in the direction of the Earth!  To date, no alien signals have been found and a more mundane mechanism such as a cluster of orbiting comets is the likely explanation.  A nice article can be found here: http://www.skyandtelescope.com/astronomy-news/curious-case-of-kic-8462852-102020155/

Here is an image of the field around KIC8462852 taken on November 8, 2015 from KSE Observatory. The comparison and check stars are indicated on the image and the dimmest stars visible are approximately 17.5 magnitude.

Click on the image to enlarge.

The unusual light fluctuations are shown in the collection of plots below:

Click on the image to enlarge.

 A plot of the light curve of KIC 8462852 from AAVSO data over the last two months is shown below:
The data points brighter than 10.8 are probably erroneous.

Click on the image to enlarge.

December 5, 2014: The rapid fading of the cataclysmic variable star KU Cassiopeia.

KU Cassiopeia is a cataclysmic variable binary star of the SS Cyg type which exhibits rapidly rising and falling outbursts. It last erupted on November 23, reaching a peak visual magnitude of at least 13.5. The rise of the light curve is very rapid, reaching peak brightness from a quiescent level of less than 18th magnitude in just a few hours. The decline back to the quiescent level is also fairly rapid for a cataclysmic variable, taking less than seven days during this last outburst. KU CAS was measured at magnitude 20.5 +/-1.4 (V) on December 5th, making this star one of the faintest objects imaged from KSE Observatory to date.  A plot of the light curve from AAVSO data over the last two years is shown below:

Click on the image to enlarge.

Below are images of KU CAS taken at KSE Observatory during and after the most recent outburst. Click on an image to enlarge.

KU CAS at 13.645 (V)

KU CAS at 13.979 (V)

KU CAS at 20.5 (V)

Time series data taken November 27 and 29th did not show clear patterns over the four hours of observation on each night. The orbital period is listed at 60 days for this system so it's not surprising that the light curve is generally featureless except for a slow decline in brightness over the four hour observation period. Below is the "quick look" plot from the AIP4WIN software which was used to reduce the data on Nov. 29. Each measurement was produced from two minute exposures through a V filter. The points in the top half of the image represent the brightness of KU CAS while the points in the bottom half represent the brightness difference between the comparison and check stars (140 & 144 respectively). See the AAVSO finder chart below for star identifications.

Click on the image to enlarge.

October 29, 2014: "Superhumps" in the light curve of the dwarf nova VSX J213806.5+261957.

VSX J213806.5+261957 is a cataclysmic variable binary star of the WZ Sge type which erupted on October 21, reaching a visual magnitude of at least 9.7. Dr. Matt Templeton of  the AAVSO comments that " its recurrence time of less than five years makes it notable among stars of this class". The AAVSO requested observations of this star, including time series photometry,  in order to gather data on the evolution of the light curve following the outburst. The AAVSO Special Notice #388 link is here: http://www.aavso.org/aavso-special-notice-388

The stars which make up this binary system are in very close orbits with each other, completing an orbit about a common center in approximately 1.5 hours. This can be seen in the light curve from images obtained on October 29, 2014 (UT) at KSE Observatory:

VSX J213806.5+261957

The top curve represents the V-filter magnitude of the variable star and the bottom curve represents the brightness difference between the comparison and check stars. A total of 276, 30 second exposures were made and the light curve spans about four hours of observation time.

A superhump is an elevated outburst in the signal that occurs with a period slightly longer than the orbital period. Two complete superhumps can be seen in the "Quick Look" photometry data plot above. The superhump may be the result of an elongation of the accretion disk in combination with precession. The elliptical disk precesses about the white dwarf over a time interval much longer than the orbital period, causing a slight change in the orientation of the disk over each orbit.

As of November 21, 2014 VSX J213806.5+261957 has faded to about 14.5 magnitude. The AAVSO generated light curve is shown below:

Click on the image to enlarge.

VSX J213806.5+261957 and the comparison/check stars are identified in the KSE Observatory image shown below:

Click on the image to enlarge.

May 4, 2014: An occasional look at nearby galaxies.

With Leo overhead and a rich cluster of bright galaxies following the constellation, I gave into the temptation to image some of the brighter spirals for a chance to stumble on a supernova in the making. Not much luck on that night, which isn't surprising considering that the rate of supernova events in any given galaxy is about one per hundred years!

Here's an example image of NGC 4565 as it appears after an 11 minute exposure through a photometric V filter.

Click on the image to enlarge.

Observing goals:

Most of the observing time at KSE Observatory is devoted to variable star CCD photometry in support of AAVSO observing campaigns and special activities. Objects of interest include cataclysmic variable stars (CV's), high mass x-ray binaries (HMXB), polars, blazars (BL-LAC objects), and extrasolar planets. And there's an occasional solar system planet, asteroid, or comet that also makes the list.

Partial target list:

J2030.5+4751 (High Mass X-Ray Binary)
HBC 722 (Young stellar object)
BL Lac (Blazar, AAVSO High Energy Network target)
IL Aqr (Magnetically active dwarf, AAVSO Alert #406)
3C454.3 (Blazar, AAVSO High Energy Network target)
V455 And (AAVSO Alert Notice #426)
1ES0120+34 (Blazar, AAVSO High Energy Network target)
TT Ari (Monitor for low state)
3C 66A (Blazar, AAVSO High Energy Network target)
1H0323+342 (Blazar, AAVSO High Energy Network target)
AAVSO 0434+41 (High Mass X-Ray Binary)
NSV 16181 (Magnetically active dwarf, AAVSO Alert #406)
V998 Ori (Magnetically active dwarf, AAVSO Alert #406)
FS Aur (Peculiar Dwarf Nova, AAVSO Alert #428)
SAX J0635+0533 (High Mass X-Ray Binary)
1ES0647+25 (Blazar, AAVSO High Energy Network target)

OI 158 (Blazar, AAVSO/GTN High Energy Network target)

YZ Cmi (Magnetically active dwarf, AAVSO Alert #406)

1ES0806+52 (Blazar, AAVSO High Energy Network target)

MRK 1218 (Blazar, AAVSO High Energy Network target)

OJ 287 (Blazar, AAVSO/GTN High Energy Network target)

NSV 4776 (Magnetically active dwarf, AAVSO Alert #406)

FIRST J1023 (Neutron star binary, millisecond pulsar)

RY Sex (Magnetically active dwarf, AAVSO Alert #406)

EE Leo (Magnetically active dwarf, AAVSO Alert #406)

CN Leo (Magnetically active dwarf, AAVSO Alert #406)

MRK 421 (Blazar, AAVSO High Energy Network target)

3C 273 (Blazar, AAVSO High Energy Network target)

3C 279 (Blazar, AAVSO High Energy Network target)

Artist's depiction of DQ Herculis, an intermediate "polar" CV binary star.
Image courtesy of NASA/nasaimages.org
Click on the image to enlarge.

A super-massive black hole at the center of galaxy M87 beaming a jet of electrons and sub-atomic particles. Strong magnetic fields and the spin of the black hole are thought to produce the narrow jets which shoot out from the poles in opposite directions. Blazars are galaxies such as M87 where the jet of particles is directed at our line of sight. Image courtesy NASA/hubblesite.org
Click on the image to enlarge.

An artistic view of the accretion disk and the jet of a blazar. Credit: Cosmovision, a group led by Dr. Wolfgang Steffen of the Instituto de Astronomia, UNAM, Ensenada, Mexico.
Click on the image to enlarge.