The Graze of SAO 161257 on Sunday evening Oct 18, 2015

This graze of the famous bright Cepheid variable star WZ Sagittarrii (mag 7.5-8.6 range) passes just north of Aromas, nicely convenient for the "brain trust" of the Cabrillo Astroheads - me and Becky - and also is at a convenient time of night. It's listed as 7.7 mag star (7.1 in R) and at phase 3% so essentially at maximum light. It occurs at 18 degrees altitude on a 32% waxing moon, 5 degrees from the southern cusp. The thin cresent cusp is on the far right of the profile on the "sea level" curve.

The central graze time is 8:50:27 pm local time for the 4.5km N site and a couple seconds later at the 2.45km site.predictions

Best tracks:
* 2.45km North on the edge, feast or famine!
* 4.30km NOrth. Latitude = 36 52' 24" for GPS'ing on the road, this is on McGowan Rd
* 3.9 km North. at driveway and Trafton Rd. See map.

 

map

The profile has two good sites; one a bit risky at the very edge of the moon at 2.75km north, and the other is better and more forgiving at 4.5 km north.

The 4.3km north site is very familiar to me, having biked by it many times on south county rides. It's off Beach Rd, just east of the bridge over the Pajaro, and next to a small white structure on the south side of the road. If it's dry, it's fine to pull off the road.

2.45km on farm road

   

Post Graze Report:

Good success! Becky and I each had 8 events, on McGowen Rd. Becky's final "R" was on the bright peak at +2min on the profile. For me also, but the peak clearly brightened on the video by 2x or 3x so it's a solid R for me. Kirk had ~6 mountains?, getting the early hills which were too low for Becky and I to have. He saw the star merge with the sunlit peak and did not note the peak dimming as the star disappeared. He'll be reducing his graze using .mp3 software. Kirk was 22 ft SW of the centerline of the driveway. Becky was 47 feet SW of the centerline of McGowan Rd on the north side dirt road along the culvert. I had VTI-GPS stamped on my video for coordinates.

Kirk: lat=36 52' 12.88" long=121d 47m 12.14s elev=13 ft.
Becky lat=36 52' 20.74" long=121 47m 12.88s elev=13 ft.
Rick Lat=36 52.4159, Long=121 47,2775m elev=13ft.

Kirk's graze timings:


graze of WZ Sagittarii 

2015/10/18 Watsonville


elapsed UT event

mm:ss.ddd hh.mm.ss.ddd

04:28.175 03:49:00.000 UT minute

04:48.635 03:49:20.460 D

04:50.167 03:49:21.992 R

04:54.267 03:49:26.092 D

04:59.988 03:49:31.813 R

05:05.161 03:49:36.986 D

05:28.177 03:50:00.000 UT minute

06:21.030 03:50:52.853 R

06:28.178 03:51:00.000 UT minute

07:28.050 03:51:59.872 D

07:28.180 03:52:00.000 UT minute

07:36.594 03:52:08.414 R