V404 Cygni article published

I was lucky enough to be named as a co-author to an article about this target published in the scientific journal Nature, January 7, 2016.  Here's a link:

Nature article about V404 Cygni

There was also a article published by my variable star astronomy group, AAVSO at:

AAVSO article about observers helping with the science

Very cool...

V404 Cyg in outburst!

This target in the constellation of Cygnus, V404, is known to be a black hole binary paired with a near solar mass companion.  On June 15, 2015 it went into outburst rising from magnitude 19 to about magnitude 12.

I first observed the target on June 19 and the outburst was continuing.  Here is a light curve of it's activity.



This chart contains observations over about a four hour period.  The dark dots show the changes in brightness over the period, the red dots show a nearby comparison star which as you can see, is unchanging.  Each dark dot is a 30 second exposure, measured with photometric software.  Since each dot is 30 seconds, changes in brightness at the two or three minute level can be seen.  Very exiting.

C14 nearing completion

My C14 rebuild project is coming to completion.  I started with a 1980's vintage orange tube C14 with plans to make it a photometric 'patrol' scope; one that would image many target in one evening looking for outbursts or other changes.  For this type of slewing the mount would have to be modified with good quality bearings in declination and good drive gears.

I rebuilt the declination bearings with ball bearings and installed a precision Byers gear.  I bought a Byers 'retro-fit' polar housing from Byers.

Here's the scope with most of the components mounted but not cabled up.

Changes to W30

We've made two changes, added a guider so that longer exposures are possible and added a longer dew shield.

We've had some trouble with glints of stray light on some images during bright moon times.  Hopefully the longer dew shield will reduce that.

Interestingly, although the company that makes the guider advertises it as a guider, it has to be used with a star diagonal as the light path is too long to mount the guide camera in the focuser.  So it's not designed as a guider at all.

Cool data...

Here is a cool light curve that jumped out at me.

The target is PNV J19150199+0719471  which is a newly discovered cataclysmic variable in Aquila.  This is about a 4 hr. run, each dot is a 60 second observation with a CCD camera and yes, those are error bars!  The precursor object was about 20th mag, here you can see it's varying around 15.8  The target is showing a 87 minute period.  This sawtooth pattern is referred to as 'superhumps'.  The model says this is oscillations in the accretion disk swirling around the white dwarf as the matter pours on to it.  It's pretty dramatic…

Confirmed a new supernova in NGC 7331 with this image.

Position
22 37 2.07  +34 24 2.92

It's the upper of the close pair.

W30 has a new home

W30 is a 12" Meade SCT donated to the AAVSONet by the estate of Paul Wright, a former AAVSO member.  The telescope is equipped with an SBIG STL-1001 camera and photometric filters. It runs a nightly program of variable star imagining gathering hundreds of images.

A new steel pier was added to the observing floor to support the telescope.  Several nights of work were required to get the polar alignment right and the focusing system working properly.