A CLOUDED ECLIPSE

by Lorenzo Comolli

Jiaxing, China (100 km SW of Shangai), 30° 44’ 01.6" N, 120° 47’ 18.7" E, 50 m

I've observed the eclipse with a group of 100 amateurs of UAI, the Italian Astronomical Union. Unfortunately in Jiaxing the eclipse was completely clouded. Nothing was visible of the Sun except the great darkness during the totality, and a few minutes of partial phases. Here are a few results.


Totality and landscape

This is one of the only images of totality: clouds, clouds, clouds. The orange lights from the horizon is not the 360° light of the eclipse but the light pollution of Jiaxing (center, 3.5M people) and Shanghai (right, 20M people). In the South direction (not imaged) the horizon was completely gray.
Below the clouds, we are hoping for a possible aperture, while walking in the flooded football field. Fortunately the heavy rain stopped just for a quarter of an hour centered on totality. My telescope is at left, below a gazebo, shooting automatically a lot of unusable black images. The authors are in the center and in the right part of the image. Thanks to Giorgio for this collaborative image: his DSLR and tripod, my objective and intervalometer.
Technical data: Canon EOS 400D, RAW, 400 ISO, Peleng 8 mm f/5.6, exposure 5 s, h 1.39.37 UT. Authors: Lorenzo Comolli and Giorgio Silvagni.
Time-lapse of totality
Subject: Clouded total solar eclipse from China
Date: 22 july 2009
Location: Jiaxing, near Shanghai, China
Camera: Canon EOS 400D
Sensitivity: 400 ISO
Objective: 8 mm f/5.6
Exposure: Auto (from 1/6 to 5 s)
Intervals: 15 s

Formats: AVI and SWF

Authors: Lorenzo Comolli and Giorgio Silvagni


Partiality

My only image of the eclipse, during the exit partial phase, between the clouds that filtered the light. Technical data: Canon EOS 5D, RAW, 100 ISO, Pentax 75 apo refractor, focal length 500 mm, f/6.7, exposure 1/15 s, glass solar filter, h 2.14.17 UT.

Illuminance measurements
The only scientific measurement possible during the eclipse was the meteorological observations. Unfortunately the heavy rain turned off my temperature and relative humidity gauge, and the only working instrument was the luxmeter. During totality the illuminance was very low, down to a value of 0.1 lux, the minimum value measured by the gauge. This is a lot lower respect to the 2006 total solar eclipse, when a minimum of 4.1 lux was reached. This is mainly due to the clouds that absorbed the daylight. The totality zoom shows a non-symmetrical trend, with a brighter part toward C3. This should be due only to the clouds thickness.
Here is the obtained graph, both in linear and logaritmic scale.





Images of the observing field
The observing field was inside a bix complex of schools, totalling 10000 students, named "five schools". Our group observed from a football field, that unfortunately filled up of water due to the heavy rain. The organization kindly provided many gazebos that allowed us to protect the telescopes. Here are some images.


Google map with the eclipse details for the observing field.


Our exact geographical position


My instruments: Pentax 75 on an equatorial mount and a 20x80 binocular


The instruments out for a while waiting for a hole in the clouds


Rain, rain, rain: all under the gazebo


Under the gazebo we hope for a better weather


Imaging the bad weather


The neighboring gazebo




Any football match would be suspended for heavy rain...


My instruments covered with a black bag to be protected from the heavy rain.


The only scientific instrument able to record the eclipse: the luxmeter.



Some days before... a circumhorizontal arc (CHA) over the Great Wall
Two days before the eclipse our group was visiting the Great Wall, and we've observed a very nice circumhorizontal arc (CHA). Here are some images. Thanks to our friends to note such an event: Lucio Furlanetto, Alberto Dalle Donne, Enrico Finotto.




Detail of the CHA over the Great Wall


Wide field view




Colours in the clouds near the Sun.



Every comment on the images is highly appreciated, please write to comolli@libero.it 



HTML Editing and Publishing by Lorenzo Comolli. Il mio e-mail è: comolli@libero.it.