PM Saturday, September 27 - AM Sunday, September 28, 2014 - Observing Notes

  Saturday the 27th was partly to mostly cloudy during the morning with mostly high clouds but some low clouds. The afternoon, however, cleared up quite nicely and high clouds were scarce. Winds were mostly light with some moderate afternoon winds, and we went from the mid-50's°F near sunrise to a little above 80°F during the afternoon. The Dew Point ranged from the low to mid 50's°F so except for the early morning the air stayed pretty dry. It was mostly clear at sunset with a few clouds hugging the West and North horizon.

  At deep dusk I walked outside to the patio and had a glimpse of the Waxing Crescent Moon partly obscured by tree foliage low in the Southwest. A bright object was less than 3 degrees away to the east of the Moon, and I later learned that this object was Saturn. Mars also would have been visible about 22 degrees away to the east and south, just 3 degrees above Antares, but these last two objects were lost in thicker tree foliage from my vantage point on the patio. The Moon was about 3.8 days past New Moon when I saw it, in Western Libra.

  I'd debated whether or not to get the telescope outside to do some observing, mainly because satellite images showed lots of clouds scooting away to the North and Northwest parts of the state but more moving toward us from Southern Indiana. It didn't look as if the clear sky would stay with us for long. The high pressure that's been with us all last week is still parked over the Eastern Great Lakes, but weak systems out in the Great Plains and along the Gulf Coast keep trying to stream clouds into the Western Great Lakes and the Ohio Valley.

  However, around 8:45 PM I thought I remembered something I'd looked up last week, and searched SY Andromedae online using VSX. I was right; mid-eclipse was predicted for 6:07 UT September 28, or 2:07 AM Sunday morning our time.

  I'd observed this star out of eclipse a couple of times last summer, but before this there were no estimates in the AAVSO database since 1998! Just to help commit this to my own memory, SY Andromedae is an eclipsing binary (EA type) with a range listed as 10.7 - 12.2 magnitude and a long period of 34.90847 days (34 days 21 hours 49.8 minutes) and the eclipse duration is listed as 6%, so each eclipse lasts about 2.09451 days (2 days 2 hours 16.1 minutes). It should take roughly 25 hours from the start to the middle of each eclipse and the star, if the brightness drop was linear, should drop about 0.1 magnitude every two hours (very roughly!).

  Session #1 - 9:15 PM - 9:50 PM (1:15 - 1:50 UT Sept. 28)

  Knowing that I could catch SY Andromedae getting toward eclipse, if the predictions were right, I started setting up the telescope. I had it plugged in with the dew cap on and pointed near M-31 (the Andromeda Galaxy) by 9:00 PM. It was clear outside with maybe a very light haze in the air. The wind was calm and crickets and other singing insects were chirping and buzzing away like crazy. There was music coming from a loud party somewhere to the south in the neighborhood; typical Saturday Evening noises really! It wasn't really dewy at all. I figured out later that my naked eye limiting magnitude was about 4.8 and the telescope limiting magnitude was maybe 13.0 or slightly dimmer (I really need to clean the optics!). It was mild enough to wear a T-shirt and I didn't have any mosquito problems while I was out there. The Temperature was about 70°F, the Dew Point was about 52°F, the Humidity was about 53%, the Wind was from the Northeast at 5 mph and the Pressure was 30.14".

  By 9:22 PM I had the Andromeda Galaxy M-31 in the telescope under 39x power with it's central glow plainly visible. The satellite galaxy M-32 stood out easily, but I can't say with any confidence that I could see the other satellite galaxy M-110 at all! I guess I'll chalk that up to some murk in the sky and maybe light pollution. This area was also still fairly low in the East-Northeast. I star-hopped from this to the area of my variable about five degrees away, and found it by 9:28 PM.

  9:35 PM (1:35 UT Sept. 28) - I estimated SY Andromedae as 12.1 magnitude. This was a difficult estimate and I had to use 203x power to make out the variable and comparison stars, but I'm very confident with the estimate. I used a star at RA 00:13:17 Dec +43:43:58 (approximately 11.9 mag.) and another at RA 00:13:11 Dec +43:41:12 (approximately 12.6 mag.) for the comparison stars. The coordinates are 2000.0 and the brightness of these stars came from the Calsky.com website last year, which uses the USNO catalog as far as I know for faint stars and the Tycho and HIP catalog for brighter stars. I used Chart 11953BPA. The 12.6 star was very tough to see and I only glimpsed it from time to time. The 11.9 star and SY And were fairly easy to make out. The ratio seemed to be 11.9 - 1/3 - SY And - 2/3 - 12.6 to me and I'm sure this is accurate to at least +/- 0.01 magnitude. SY And was slightly but definitely dimmer than the 11.9 star, which usually implies a 0.02 magnitude difference from past experience. This star was definitely in eclipse!

  This is my "makeshift" AAVSO Chart for SY Andromedae used when making this estimate:

  9:46 PM (1:46 UT Sept. 28) I estimated VX Andromedae as 8.2 magnitude. This was a far easier estimate to make and I used 39x low power. I used the 7.6 and 8.5 comparison stars on Chart 11953BPI (this chart hadn't been revised since I printed out in the summer of 2013). The ratio seemed to be about 7.6 - 2/3 - VX And - 1/3 - 8.5. I had to be careful not to stare at this star for too long since it's much redder than most of the surrounding stars. It's an SRA with a period of 375 days, and I mainly estimated it because I estimated it last summer and it's close to SY And and easy to find. I am confident with this estimate.

  After this estimate I put the eyepieces and the telescope OTA inside and left the mount and tripod and cords outside, unplugged. I did this because I wanted to check sky conditions later to see if it stayed clear enough for more observing, but I didn't want the optics to get dew covered.

  Session #2 - 12:20 AM - 12:35 AM (4:20 - 4:35 UT Sept. 28)

  I went outside just after midnight to see that there were a few visible high cloud bands around, and satellite images online showed a lot of thicker clouds streaming quickly toward Indianapolis from the Southwest. I decided I'd better hurry and get the OTA back onto the mount and make another estimate for SY Andromedae. I had it all back together and got my charts and voice recorder back outside by 12:20 AM. By this time the thicker high cloud bands were moving in and I was racing with them to make the estimate!

  By 12:25 AM I had the Andromeda Galaxy M-31 back in the 39x field of view. M-32 still stood out easily, and, in spite of the increasing "murk" and high clouds, I was able to see M-110 as a slightly brighter glow against the background. Maybe the higher position in the sky had something to do with this?

  12:33 AM (4:33 UT Sept. 28) - I estimated SY Andromedae as 12.2 magnitude. I once again used the 11.9 and 12.6 magnitude comparison stars on Chart 11953BPA (see the earlier estimate in this entry for the start coordinates and the source of the magnitudes). I had several good looks at this star under 203x power and I kept checking the sky to make sure the big bands of cirrus clouds were still keeping clear of this part of the sky (they surrounded it bit didn't encroach on it). I also did my best to stay unbiased, but it seemed clear that SY And was between these two stars in brightness and just slightly closer to the 11.9 star. There did seem to be a bigger difference now between SY And and the 11.9 star than there was three hours before.

  The sky was about half-covered with thin cirrus clouds when I made this estimate. In the clear areas I thought my limiting naked eye magnitude was still about 4.8 and my telescope limit was still about 13.0 - 13.1. It felt a little cooler than it had felt earlier in the evening but I was still comfortable in a T-shirt. Of course I wasn't out very long! The Temperature was about 64°F with the Dew Point at 51°F and the Humidity was 63%. The Wind was still from the Northeast at 5 mph and the Pressure was 30.14". I didn't feel a breeze at all. Crickets and other singing insects were still fairly loud. The neighborhood party I'd heard earlier in the evening seemed to be over, but there was still some local car traffic and some distant traffic. There were some neighborhood dogs barking.

  I had the telescope inside by 12:45 AM and called it a night. If it's clear this evening (Sunday evening EDT) it might be valuable to make one or two more estimates of SY Andromedae, since the eclipse probably won't be totally over until about 3:00 AM Monday morning EDT. Though tonight's session was cut off a little by clouds, I was glad to see one of my "personal program stars" fading into eclipse, and I was glad that this was the third time in less than a week that I'd been out looking at variable stars through the telescope, after not doing any variable star work with it since last September!