Notes & Observations from Nick Quinn, G0BAF
Stacked image (5 x 4 minute integration) of near-Earth object 1999 VU imaged with Celestron C11. Magnitude 16.7. This is an Apollo-type body, about 2.885 km in diameter. See http://minorplanetcenter.net/db_search/show_object?object_id=17182
It doesn’t appear to pose any threat to the Earth: http://newton.dm.unipi.it/neodys/index.php?pc=1.1.8&n=1999VU
Observer
Longitude: 000° 19′ 57” West; Latitude: 50° 53′ 16” North; Altitude: 20m (WGS-84)
Equipment
Celestron C11 f/10 focal length:2800mm diameter: 280mm
SBIG STF-8300M binned 2 x 2, subframe 1429 x 655 (binned) pixels
Filter: Luminance (Astronomik)
Imaging
Integration time: 2 secs
Dead time: approx. 2 secs for download & file save
Processing
AIP4WIN
Bias & dark-frame subtraction, no flat-field applied
Photometry measurements using ‘Multi-Image Photometry’ tool
Radii chosen to minimise contamination from Neptune
Results
Ingress ½ light estimated at 23:47:17 ±4 seconds
Egress ½ light estimated at 23:49:41 ±4 seconds
The published paper analysing the results published in Astronomy & Astrophysics can be found here: Constraints on the structure and seasonal variations of Triton’s atmosphere from the 5 October 2017 stellar occultation and previous observations
The view from east to south from our observing site:
Here is a composite of partial and total phases:
The Total eclipse of 2017 August 21 as observed from: near Riverton, Wyoming Phase Time P Z Altitude Azimuth 1st Contact 16:19:56.2 287.7 330.0 41.1 116.0 2nd Contact 17:39:37.4 130.7 159.9 52.7 139.2 Maximum 17:40:44.3 19.0 48.0 52.8 139.6 3rd Contact 17:41:51.4 267.5 296.2 52.9 140.0 4th Contact 19:06:01.3 110.3 113.5 58.8 175.7 Duration: 2 Mins 14 secs (134 secs) ** not limb corrected ** Magnitude: 1.0291 Obscuration: 1.0000 Ratio Moon/Sun: 1.0291 Longitude: 108.0491 West Latitude: 42.9609 North Height: 1681 metres
Preliminary processed image. Tamron 500mm f/8 catadioptric lens. Stacked 1/125 – 1 sec exposures.
2nd Contact
3rd Contact
Image taken with 8 inch Altair RCOS and SBIG STF-8300M. 16 minute (4 x 4) exposure through ‘luminance’ filter.
Here is the annotated image from Astrometry.net identifying the other galaxies within the field.
From Wikipedia:
NGC 51 is a lenticular galaxy in the constellation Andromeda. It has a diameter of 90,000 light-years. The galaxy was discovered on September 7, 1885 by Lewis Swift, who described it as “Pretty faint, pretty small, round, brighter middle.”
| Observation data (2000.0 epoch) | |
|---|---|
| Constellation | Andromeda |
| Right ascension | 00:14:34.8h |
| Declination | +48:15:22° |
| Redshift | 0.017849 |
| Helio radial velocity | 5350 km/s |
| Distance | 241,000,000Ly (74,000,000Parsecs) |
| Apparent magnitude (V) | 13.1 |
| Characteristics | |
| Type | S0/a |
| Size | 90,000 |
| Apparent size (V) | 1′.445 x 0′.891 |