After the two successful nights in northern France , a number of clear nights followed in June in the Netherlands. As I sometimes suffer from hay fever, I could not observe every clear night. In addition to observing meteors, I have also seen 5 NLC displays, but unfortunately not the big outbreak of 21 June. Here are the night reports:
22/23 June 2019
A full moon on June 17 means that observations become soon possible again. The evening of July 22 was clear, so the observations started at 22:30 UT. Location: Groevenbeekse Heide (a heath). Unfortunately, the sky was very hazy so the limiting magnitude did not exceed 6.1, the SQM reached only 19.98. The moon would rise around 23:20 UT, so the session ended after exactly one hour. This resulted in only three meteors, 2 sporadics and one possible early July Pegasid (+3).
28/29 June 2019
The sky cleared up nicely in the evening of the 28th of June. I went to bed early that evening to be able to observe rested later that night. When I was awake and looked at my phone, the messages about the big daylight fireball from earlier that evening also came in. My neighbors have also seen and heard the thing from the heath nearby and it must have been an impressive event. I still thought: why not a few hours later?
This night the sky was very transparent and despite the “gray nights” I achieved a limiting magnitude of 6.3 and a maximum SQM value of 20.25. During this time of the year the observing window is always very small. I could count meteors between 22:27 to 00:35 UT. During this 2.10 hour I observed 18 meteors. Some nice meteors appeared. At 23:34 UT a beautiful bluewhite magnitude 0 sporadic meteor appeared moving through Cygnus. Five seconds later followed by another weak meteor. And a slow +4 ANT was, despite the brightness, also worth the sight.
A successful night, the starry sky was beautiful with a beautiful Milky Way visible from Cassiopeia to the northern parts of the constellation of Sagittarius. Every now and then a large owl came flying by low, also some small bats. Unfortunately, there was noise coming from the village, there are always parties with live artists on Saturday evenings in the summer.
29/30 June 2019
Figure 1. On 28 June 2019, Sahara sand hung above the southwest
of the Netherlands and above the North Sea.
Again a clear sky. I was surprised when I looked outside around 20:30 UT, I saw elongated bands of yellow clouds hanging in the west. They were also visible on the SAT24 website. It turned out later that it was Sahara sand that was blown to western Europe with southern winds.
An hour later there was nothing left to see. At 22:20 UT I cycled to the heath and the circumstances were just a little less and only at very low altitude compared to the previous night. Our Dutch Meteorological Institute KNMI expected minimum temperatures of 18-20 degrees Celsius tonight. However, when I cycled up the heath it felt much colder, it turned out to be 14 degrees Celsius. This dropped further to 12 degrees, but in the last half hour a southeastern wind came up firmly and the temperature rose again to 17 degrees at 00:35 UT.
This night the great owl also flew over again and sometimes also bats. There were also two other events that were noticeable.
When I arrived at my observing location, I saw a LED light on in the heather bushes next to my observing place. I thought what lies there? An electronic device with burning voltage indicator? Had I something forgotten from the previous night? I already saw it from a few meters away. Upon closer inspection it turned out to be a firefly. However, these are not real flies but beetles. I have heard many times that people have seen fireflies on the Groevenbeekse Heide, especially on the forest edges at dusk. But for me this was the first time. Such a small insect gives a lot of light, because the surrounding heather twigs and grasses were dimly lit. The insect remained visible until around 23:30 UT. Days later, after a hot summer day, I cycled again with my wife Lizzie along the edge of the forest during dusk. We saw two firefly’s then. This is something we want to do more often because it gives a mysterious touch to the forest and the twilight.
And the meteors? Observations were made between 22:24 and 00:36 UT (t.eff. 2.17 hours). Despite the fact that the sky was slightly less at a very low altitude, the sky background seemed slightly darker. Indeed, SQM values were slightly higher compared to previous night: 20.30. Limiting magnitude was 6.3 at most. In total I counted 15 meteors.
At 23:04 UT in the constellation Aquila, very slowly a bright greenish light moved southwards. For a moment I thought about an Iridium flare, but it went too fast. So, a bright fireball of about magnitude -6! Very beautiful, especially the color. The fireball was photographically captured with my all sky camera, but (as I already expected) most breaks were molted due to the very slow movement of the fireball. All in all, a successful night.
Figure 2. The fireball of 29 june 2019 23;04 UT. Camera: Canon 6D, lens Sigma 8 mm F 3.5 .
30 June / 1 July 2019
Third night on a row! During the long evening twilight, a short visit was first made to a family in Harderwijk who had recorded the daylight fireball of June 28 on video. Some pictures of the starry sky were made for Marco Langbroek. Unfortunately, the images from my camera could not be matched with the video recording of the fireball.
Afterwards, immediately into the field. During this bycicle ride to Ermelo and later to the heath, the all sky camera captured two fireballs of magnitude -4 very low in the south, but unfortunately, I did not see both of them.
The quality of the night was just a little less than the two previous ones. I observed between 22:35 and 00:10 UT. Indeed, observations were stopped earlier, this due to incoming clouds that entered my field of vision from the north.
Only 12 meteors counted during this session. The most striking were the first meteor (a slow +3 Antihelion) and a +2 sporadic meteor.
Figure 3. This fireball was captured on 30 june 2019 between 22:25:30 and 22:26:58 UT.