V1403 Cygni Notes

  Monday June 16 started out with thunderstorms brewing. During the middle of the morning a hefty cell rumbled through Indianapolis with frequent lightning and thunder but only scattered heavy rain. My rain gauge at home had just a Trace in it, and the storm center seemed to mainly pass south of us. By late morning the sky cleared out somewhat and we had partly to mostly skies for the rest of the day. There was a lot of haze that made even the blue sky look whitish. And though there were no more storms or rainfall in Indianapolis for the rest of the day, the humidity was just awful! The dew point reached 70°F by afternoon and stayed there through sunset. It was a real steam bath even though the afternooV high temperature only reached the mid-80's°F.

  I worked from Monday afternoon until a little after 1:00 AM Tuesday morning (June 17), and drove back from Greensburg to Indy by 2:30 AM. It was obvious that this wasn't going to be a night out with the telescope. The sky had scattered high clouds lit up by moonlight from the bright Waning Gibbous Moon (about 4 days past Full Moon) and even the cloud-free parts of the sky were covered in haze. It was difficult to make out 3rd magnitude stars with the naked eye. There was a breeze stirring the leaves, but the air felt thick and muggy. The eclipse of V1068 Cygni was underway. Maybe I'd luck out and have clearer skies on Wednesday morning when it should be near minimum brightness.

  So instead of observing one "neglected" eclipsing binary star, I'm going to go ahead and write about another one I've put on my list to observe, just a handful of degrees away. Here's the information that I've gleaned about it:

  Star Name: V1403 Cygni
  AUID # : 000-BDP-268
  Harvard # : None
  Variability Type : E (In other words, no one seems to know for certain what kind of eclipsing binary star it is. It could be an Algol type EA, a Beta Lyrae type EB, or maybe even a W Ursae Majoris type EW.)
  Magnitude Range: 10.8 - 11.2 P
  Period: Unknown
  Eclipse Duration: Unknown

  There's so little known about this star that it caught my eye. Though the brightness range is small, I should be able to detect a 0.4 magnitude change if I observe it on as many nights as I can. The AAVSO database has no estimates for this star at all. The Lichtenknecker-Database of the BAV lists three estimates for it, credited to Miller and Wachmann. These were measured from photographic plates. Two of the estimates are from July 15, 1950 and one is from November 6, 1950.

  To sum it all up, I may, very soon, be the first person to observe V1403 Cygni in 64 years! More importantly to me, I may be able to help determine its nature with some careful visual estimates. Now all I need are some less murky sky conditions!

 
 

V1068 Cygni Notes

  Though I still haven't done any variable star observing this year, I've been slowly compiling a list of "neglected" eclipsing binary stars, gathering what information I can about them, creating charts for them from the AAVSO website, finding comparison star sequences for the variable stars that don't have them, and creating finder charts for them from my Starry Nights planetarium program. I've also been checking the VSX website for any eclipse predictions for these stars, though some of them have unknown periods, and therefore don't have predictions. It's been fascinating!

  One of the ten or so eclipsing binary stars on my list is fairly close (5° away) to the very familiar cataclysmic variable star SS Cygni. And, if predictions are accurate, it should go into one of its long eclipses during this coming week. Here's what I've gleaned about this star:

  Star Name: V1068 Cygni
  AUID #: 000-BFR-960
  Harvard #: None
  Variability Type: EA/GS/RS
  Magnitude Range: 10.5 - 12.1 P
  Period: 42.6813 days (42 days, 16 hours, 21 minutes, 4 seconds)
  Eclipse Duration: 7.5% (3 days, 4 hours, 49 minutes, 35 seconds)

  The VSX website notes "A migrating wavelike distortion with an amplitude ~0.1 mag. V is being observed outside eclipses."

  The AAVSO Database currently has no estimates at all reported for this star, visual, CCD, or otherwise.

  The website that I've started to check religiously for these stars, the Lichtenknecker-Database of the BAV, lists 158 estimates for this star. All of them are visual or measured from photographic plates, and they start in September 1929 and end in September 1980.

  As far as I can tell, no one has reported an estimate for V1068 Cygni for almost 34 years! This might be because it takes a little over six weeks between eclipses, and the time it takes to start fading, bottom out, and rise again takes a little over three days. There is also that minor fluctuation in brightness between eclipses. That could make this star interesting to observe on any clear night.

  The next predicted eclipse for V1068 Cygni is centered at 4:54 UT June 18, or 12:54 AM Wednesday June 18 EDT. This eclipse will start around 11:00 AM Monday morning June 16 and end around 3:00 PM June 19 (Eastern Daylight Time again). The next one won't happen until the very end of July.

  I am working Second Shifts for the next two weeks and I'll be able to observe with the telescope on any clear night, on workdays, from about 2:30 AM - 3:00 AM through the start of dawn (which starts around 4:45 AM, very early this time of year when we're this close to Summer Solstice). If the predictions are accurate, it might be possible for me to see V1068 Cygni declining in brightness before dawn on Tuesday June 17, near minimum on the morning of Wednesday June 18, and rising in brightness again before the sky gets light on Thursday, June 19.

  There will be challenges. Hot and humid weather is supposed to settle over Indiana this week including chances for rain and thunderstorms. Even if the sky clears out at night, the humidity could give me murky skies with bad transparency. The bright Waning Gibbous Moon will be in the Southeast sky every morning this week. And, of course, fatigue from work could always be a factor! Still, the next few days are giving me a real chance to get started on this year's personal "neglected eclipsing binary star program" and on variable star observing again after all of these months.

  If I get clear skies this week, it's Game On!