Interesting Images

2004 MN4 Photometry
UT Time 1:54:08 3:37:13 4:31:31 5:44:38
Time in min 24.13 127.22 181.52 254.63
Mag 2004 MN4 17.16 17.44 17.51 17.70
Mag check star 17.28 17.29 17.23 17.26

 
First image, 9×9′ crop, N at top, 4 min exp.
Track and Stack used for MN4’s motion.
Data acquired by Joe Dellinger (Fort Bend Astronomy
Processing and photometry by Bill Dillon.

[1]

William G. Dillon:
Time in minutes from 1:30 UT

[2]

William G. Dillon:
Unfiltered magnitudes with respect to a comp star defined to be 17.0 (result chosen to be close to Astrometrica estimate for the first image)

 

Messenger spacecraft imaging attempt

 

The animation consists of five cropped frames (200×200 pixels) on the left (east) side of the full frame (~1000 pixels). The cropped frames above are about eight arcminutes on a side, with north at the top, and east to the left. Each image is a stack (or sum) of four 30-second exposures (with about 40 seconds between images for downloads), offset in the predicted motion of the MESSENGER spacecraft. The spacecraft (and/or its third stage) appears on the left-center side of the image as a dot moving left to right in the direction the stars are streaked. It can be seen clearly in stacks 1 and 2, and is partially visible (involved with stars) in frames 3 and 4. It seems to be lost in the glare of a brighter star in the last stack (#5). There are so many stars because the spacecraft was located in the summer Milky Way. The full image center (not this cropped portion) was targeted for 19h 23m 21s, +32 39′ 22″, based on a somewhat outdated ephemeris (MESSENGERS burn was a bit below planned, and we forgot to check for updates).The images were made on August 4 UT, using the Fort Bend Astronomy Club’s 18-inch (46 cm) reflector, amazon tv box and a Zilkha-grant Apogee AP-8 camera. Observers were Bill Dillon and Joe Dellinger. At the time, the spacecraft was about 0.0023 AU from the earth (about 210,000 miles or 350,000 km) at the time the images were taken.Image center UT times were:1: 03:36:03
2: 03:40:24
3: 03:44:45
4: 03:49:06
5: 03:53:27

WW Ceti

 

 

Two images of the cataclysmic variable star WW Ceti, in outburst on 16 Oct 2002 UT at V magnitude 11.15 (2-minute exposure), and near minimum at V magnitude 15.29 (6-minute exposure) on 9 Nov 2002. The images were taken on GRB team practice nights, and the data turned in to theAAVSO.

Images where taken with an AP8 camera on the FBAC’s 18 inch reflector through a V band photometric filter. The images have north at the top and have been cropped to about 1/8 degree on a side. The star just to the upper right of WW Ceti is magnitude 16.3.