Reports Report 2155a (Event 2155-2015)

Observer
Name Brian B
Experience Level 3/5
Remarks I'm maybe a 3.5 of your observing experience scale: meteor watching enthusiast, but not an amateur astronomer. I am interested to learn more details about this event, hopefully from people who saw it sooner than I did.
Location
Address Lafayette, CO
Latitude 39° 58' 28.91'' N (39.974696°)
Longitude 105° 5' 28.58'' W (-105.091273°)
Elevation 1589.019531m
Time and Duration
Local Date & Time 2015-09-06 23:56 MDT
UT Date & Time 2015-09-07 05:56 UT
Duration ≈1.5s
Direction
Moving direction From up left to down right
Descent Angle 99°
Moving
Facing azimuth 88.28°
First azimuth 86.63°
First elevation 22°
Last azimuth 90.98°
Last elevation 18°
Brightness and color
Stellar Magnitude -4
Color Yellow-orange
Concurrent Sound
Observation Unknown
Remarks -
Delayed Sound
Observation No
Remarks -
Persistent train
Observation Unknown
Duration -
Length -
Remarks -
Terminal flash
Observation No
Remarks -
Fragmentation
Observation Yes
Remarks I saw 6-9 objects of slightly different sizes appear from behind a tree, they were traveling as a group, the vertical spread was about degree (maybe a bit more), the spread along the direction of travel was slightly greater, maybe 2 degrees. Some were fainter than others, they seemed yellowish-orange, then they faded out -- pretty close to simultaneously -- in about a second after I first noticed them. I assume that they were glowing before I saw them. I heard a faint boom before I saw them, which is what drew my attention in that direction, but I assume that this sound was not related because the sound should have been delayed, unless they were *very* close, and I assume this was not the case. There was no booming sound after I saw them, but I was close to a 55-mph highway with light-to-moderate traffic that was producing some masking sounds. The faint booming sound that preceded my noticing them did sound similar to fireworks, but the objects' direction of travel was incorrect for fireworks: they traveled in a straight line from a higher elevation to a slightly lower elevation, approx. north to south as I viewed them approx. due east of my location. Their speed was far slower than Geminid objects, and I'm pretty sure their speed was a bit slower than Perseid objects. I did not see a smoke trail, but there was quite a bit of light pollution, the humidity was 53%, and there were traces of thin, high-altitude clouds, probably cirrus.