Although many hosting providers now offer hosting packages with PHP and MySQL, most do not offer cron functionality, i.e. the possibility to schedule tasks. The simplest way to set up these scheduled tasks within Drupal is by means of the Poor Man’s cron Drupal module. Once installed it will check whether cron must be run whenever your Drupal site is visited.

Some Drupal themes provide their own menu system instead of Drupal’s built-in primary links menu. When enabling these fancy menus, your Drupal site may end up with two menu systems instead of one. In order to get rid of the primary links menu, you need to disable it:

1. Log in with “administer menu” privileges.
2. Navigate to to administer » settings » menus (admin/settings/menu) and set ‘Menu containing primary links:’ to ‘No primary links’. Repeat for the secondary links.

Since I recently upgraded this site from Drupal 5 to Drupal 6.2 it was about time to try out the new Views module for Drupal 6.

2007 was the year that I bought my first dual-axis mount: an Orion Sirius EQ-G. This mount is virtually identical to the Skywatcher HEQ5 with the recent motorization. Apart from it being an affordable mount with decent performance, it also features lots of interest from enthusiast amateur astronomers, either eager to enhance the mount’s performance (see the EQ6 Yahoo! Group), or even to give it advanced computerized control for free (see the EQMOD Yahoo! Group).

All facts mentioned above have influenced my final decision to get the non GoTo “SynTrek” variant of the Orion Sirius EQ-G (the GoTo version of the handcontroller is “SynScan”). Nine months later I decided to acquire an EQDIR module from Shoestring Astronomy, along with the EQCBL-01 mating cable. I then installed the free planetarium software Cartes du Ciel, the free and standardized ASCOM Platform (free, Windows platform), and the latest EQMOD ASCOM drivers allowed me to control my mount from my laptop. I was impressed by the relative ease with which all was installed and how the hardware and software collaborated without major issues.

The only real problem I witnessed was a mere usability issue: since I observe mainly on a small balcony or on a remote location, the cable connecting the mount to the PC was often in the way. For a permanent setup this most likely is not a problem, but in my case I was thinking in terms of «this can be done in a more user friendly way». Hence I decided to look at wireless solutions to replace the RS232 serial link with the mount.

Finally I bit the bullet and upgraded my Drupal 5.x based site to Drupal 6.2. I also decided to switch to the Garland theme, and added a blog.

The Moon

• Lunar Republic’s Atlas of the Moon

The earth rotates about its axis once every day. When observing an object with a telescope, we have to compensate the rotation of the earth. An equatorial mount compensates this motion if the following 2 conditions are met:

1. its polar axis is parallel with the polar axis of the earth;
2. the mount rotates about its polar axis at exactly the same rate as the earth rotates about its axis

The first condition is met if the mount is correctly set up. The procedure of setting up an equatorial mount is called polar alignment.

Note: I will shortly publish updated instructions

I take no responsibility nor do I claim the instructions given below will yield success. The instructions below are only provided for help. Please do not misuse the information provided on this page.

After a first preliminary round of simulations for my 14” f/5 project, I narrowed down the search and used some extra features of PLOP to assist in selecting the cell I want to build. This time the search was limited to cells with at most 9 support points. The results from the first round of simulations were confermed by this second round.

Computation with a true central obstruction of 75mm, allowing for refocus shift

Contents

Central obstruction: 75mm