Morning White Light images from Payson - Birch Mesa Observatory:
Here is a two part
panorama of the active regions on the suns disk today. Many medium
and small spot groups are apparent, making for a good variety
of close up images possible. Ive labeled the active regions (AR)
so you can see in the close ups which spot groups I am referring
to. This was with the Six inch AR152 stopped to 80mm at prime
focus, with a Baader wedge, Continuum filter and UV/IR blocker
and all images in this write up are with the DMK51 CCD camera
which has a native resolution of 1600 x 1200.
Next, we put in
the 2.5x Televue Powermate for some closer views of the spot
groups. Seeing varied from 2 - 3 /5 as the sun rose higher in
the sky. This 2.5x set was with the AR152 Six inch stopped to
4 inches for maximum clarity when the seeing was worse near the
horizon. Ive labeled the group number in the lower right corner
on most images for clarity. A stunning pair to start:
Next a single medium
spot cluster, showing the penumbral filaments in the area around
the dark umbra. These are about 1.5 - 2 arc seconds in width
normally. The granulation is becoming apparent with this aperture.
A beautiful clustering
of tiny pores and small spots! There must be scores of pores
here, those dark areas without a surrounding penumbra.
A small pair on
Powermate close ups. The seeing never did get much better than
3/5 but this was just enough to show the polygonal shape of the
granulation. Full six inches of aperture is used here, proving
that more aperture can result in better images even for the Sun:
Now look at those
penumbral filaments! Some very tiny pores surround this enigmatic
group as well.
Seeing was starting
to degrade after only an hour. But I managed to get a close up
of the big group of pores around the major spot complex. Oh how
I wish the seeing would stay good for hours on end! But the Sun
must rise, ground must heat up and we must say goodbye to the
moments of best seeing for the day...
the Transit later that day. Now we move to Happy Jack, about
an hour north of Payson to our observatory built on a platform
above the pine tree tops at 7000 feet elevation. Unfortunately,
the seeing was 1-2 due to very high winds. But we did manage
to get a few good shots of the event. Here is the Photo Pictorial.
I removed the 8
inch astrograph from its home made cradle, and mounted the Lunt
LS100 inside sticking out both ends. On top, the Stellarvue SV80
was mounted for white and Calcium K imaging. Both were set exactly
in parallel to facilitate quick changes with the camera without
recentering each time. The finder on the side has a rag stuffed
in it to keep the sun from burning the reticle inside to a crisp...
The mount is completely
home made, and was built to carry much larger instruments. It
has one of the VERY LAST Byers star master drives ever made,
and tracks 10x better than my Astrophysics mount back in Payson.
Images below are
more or less in chronological sequence. Ive highlighted certain
sets of images to demonstrate different aspects of the transit
from start to a point when the sun went behind some nearby giant
ponderosa pine trees. So lets get started!
Pre Transit Sun
taken moments before the start at 3:06 pm. This is a white light
view with the SV80 with key Active Regions labeled:
Next in Hydrogen
Alpha light before the transit. Lunt LS100 with Antares .5x focal
reducer to get the full disk.
Looking for the
start of the Transit with the Lunt. Gamma (mid tone contrast)
was set to a high number for low contrast and the ability to
see the disk of the planet Venus coming in over the edges of
the spicules and proms. This sequence takes just over 5 minutes.
First shot, just barely before the transit. Venus will be coming
in at the 10 o'clock position:
First contact as
a tiny nibble to the upper left. Its tiny, look carefully just
above the proms on the edge:
A few minutes later
you can now see the notch clearly:
2 minutes later:
And the final high
low contrast shot (which shows the limb and proms best)
Next I changed
the gamma to a normal low value and the sun appears as I normally
shoot it in Halpha. this is a few minutes later:
Next we will zoom
in with the 2.5x Televue Powermate on the limb to watch the ingress
more closely. A big surprise is coming...
Now with high gamma.
You can now se the back edge of the disk is still over the spicules
on the limb. This is technically before second contact, which
traditionally is a white light event.
- when the back of the disk of Venus touches the suns limb.
Now in normal contrast
the surprise - the "Ink Drop Effect", which results
from the black disk leaving second contact in poor seeing. It
is the bridge of dark connecting it still to the limb of the
sun and is purely an earths atmospheric effect and is not real.
The last vestiges
of the Ink Drop. Note that all frames in the entire imaging set
are for 10 seconds recording time as to not blur the motion of
the planet as it moves over the sun.
Now in high gamma,
you can see the planet has significantly moved off the limb.
The view now will not hold any more surprises as the planet skates
across the sun.
Full disk view
with Venus far from the limb:
2.5x close up over
a huge active region:
Light images with the SV80/Zeiss
Lets start with
a full disk view with the planet inbound:
With the 2.5x Televue
Powermate we can see the granulation starting to appear:
Now lets throw
in some power! Here in somewhat better seeing is the event with
the 5x Powermate on the 80mm:
And now for some
real fun, we put in the CaK filters and The full disk was spectacular:
And now with the
2.5x, seeing permitting a few sharp images out of many sets I
had to take because of the seeing in UV is always awful:
Now that I have
finally seen and imaged my first - and last Venus transit, Id
like to mention a few things. First, the planets movement across
the disk was far slower than when shooting a solar eclipse, allowing
longer integration times for images. It seemed like it took forever
to finally come onto the suns disk. Second, this is similar to
what we must deal with when searching the galaxy for exoplanets.
Using the transit method, we use either a ground based or preferably
a space based telescope to monitor a stars brightness and look
for drops in light caused by an exo planet crossing its disk.
The drop is very small, and as you can see from these images,
for an earth sized planet like Venus, the drop in light out put
from the sun must be practically undetectable from a distance.
Not to mention sunspots, faculae and other transient phenomenon
to deal with as well!