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Aligning an EQ mount – the smart way

The look of the polar scope

The look of the polar scope

So the polar scope in my mount is a rather basic one. It does have some constellations but they are more like drawings. The only point having been marked is a small circle where Polaris should go. And this is not enough for astrophotography – especially if the scope is not guided.

Of course one needs a few things for a good alignment, which basically boil down to knowing the geographical position of the scope and the (sidereal) time. These are things for a chart or a computer to know, not for a human, so I decided I wanted an elegant solution.

Therefore I came up with this (csillagtura.ro/polaris) script for smartphones. The script takes the user’s geo-position plus the date and time and shows the expected view plus some tech info. After adjusting the mount to show the expected view the only thing remaining is to get Polaris into the circle. I saved a shortcut on my phone’s desktop so when I tap on it, it shows me how to set up my scope.

The script has a few tweaks like the position of Polaris is J2015 instead of J2000, but I found it’s accuracy could be improved. However, it should be good enough for the next few years, and it’s made my hobby a bit easier. Needless to say, the script works for any polar scope (I have this rather basic one pictured above) in any mount (I have an EQ3) until the circle around the pole is the same and the image is inverted the same way.

If you don’t like using my site or are paranoid about it then feel free to copy the source and host it yourself – see the stuff in the grey rectangle.

project_polaris

 


The Sun 2015-08-01, 02

 2015-08-02 through a Calcium K line filter (mosaic, 150/750)I’ve seen some really nice prominences and, well, a dolphin :) I mean I was stunned to see a feature just disappear in front of my eyes while chatting (8 hours long recording sessions have their boring parts).

Instruments:
Optics: Lunt LS35T for hydrogen alpha, N 150/750 for Calcium K line
Camera: ATIK 314E 16 monochrome camera
Software: Artemis, AS!2, Registax 6, GIMP

 

(tovább…)


Veil Nebula

The previous raw material reprocessed.
20150717_21_out_veil_4_ps2_branch4_4_


Borealis Astrocamp, July 2015

M31, 30x90sec, ISO 800

M31, 30x90sec, ISO 800

It has been the third time the Borealis Astronomy Club organized its camp in Alba county, Negrilesii Valley. The area is a treasure for astronomy since it lies in a virtually black spot of the Romanian Light Pollution map. On the other hand, by day it is a pitoresque landscape with tourist attractions like the Detunata cliff and, well, another kind of tourism, the disputed mining area of Rosia Montana.

We were 8-14 people in the camp doing mostly visual observations the main instrument being a 30 cm (12″) newtonian on a dobsonian mount. Among others I myself did almost exclusively astrophotography using a motorized (but unguided) EQ3 mount and an unmodified Canon 1100D enhanced by Magic Lantern and various tele- and wide angle lenses my primary target being the Veil nebula using the Canon EF 200 mm lens at F4 or F4.5.

Here are some of the photos I captured and processed. While the Andromeda and the veil came out quite decent, I am a bit disappointed by the overall quality of the pictures. Maybe I will reprocess the raws some other time.

(tovább…)


The Sun 2015-06-22

20150622_2_z_korong_mozaik_csakkitoresek_2___kesz_sarga_

The Sun in Hα

I imaged the Sun using a Lunt LS35T Solar Scope combined with a webcam for hydrogen alpha and a MC 102/1300 with ND3.8 and K-line filter combined with a Canon 1100D, both mounted on an EQ3. While far from ideal setups (like full spectrum sensor), I managed to capture some nice shots.

The Hα disk is a mosaic of 8 frames: the solar scope has a very annyoing vignettation. A total of 20 GiB video data was filmed. Eruptions come from the same raws, edited separately and then added to the disk.

The K line images are a stack of 15 photos shot with the DSLR powered by Magic Lantern.

I detail the process below showing the stages of the imaging session in pictures. Processig was done in Canon Digital Photo Professional (raw->tiff16), Registax6 and GIMP.

(tovább…)


RPi Moontrail – Hold-csíkhúzós

Moontrail with rpi

Moontrail with rpi

After quite a few successful attempts at imaging trails using rudimentary equipment, I decided to put my Raspberry Pi B+ and its camera to work and image a moontrail.

Past attempts include a set of sunrises at both solstices and at equinox, some sunsets, an analemma and some startrails. For these I used a Canon A800 enhanced with CHDK or a FujiFilm HS20EXR unmod. The CHDK was needed to access otherwise unaccessible options like manual focus, manual shutter speed and… well, an intervalometer. But this time a cron job did the work on my little buddy, the pi.

Below I describe the process in detail which lead to the final pictures. If you wish to skip it, click here.
(tovább…)


My Dear Infected Visitors

no_black_hatsFrom time to time I go through my access log to see what’s the net up to about or against me/csillagtura. Besides the automated attacks a wordpress site usually has to face, there is the referrer spamming of which I wrote last time. Now, at least one of my visitors have the fuck_malwares malware. This just makes me sad.

Learn your ways around the net, use adblock and if you suspect something, ask around. Don’t let malwares take away your user experience, steal your passwords, privacy… f. your life. Just don’t. :(


Referrer Spam Hitting My Site

I just wanted to write a short note about how much referrer spam hits my website.

black_hat_fekete_kalapWhat is referrer spam? My access log is not public. When checking my access log I see visits coming from variuos websites as referrers, but these websites turn out to cointain nothing about my website. So I as a webmaster was practically lured to look at a website.

So I deployed a script that reads the referring address and looks for a link to my website (which would explain the referrer). I obviously had to whitelist some domains like known search engines, webmail providers and a few private forums I know my website might get mentioned in.

Here’s what I found after a special SELECT in my log:

count of spammy visits = 265
from unique web addresses (claimed by the visitor) = 116
(I leave out the addresses for obvious reasons)
from these tld’s (claimed by the visitor): ru (41), com (40), net (9), org (8), ua (3), biz (2), tv (2), su (2), xn--p1ai (1), guru (1), in (1), au (1), ae (1), uk (1), it (1), info (1), ro (1)

Each and every black hat practice makes me sad :(


Jovial Dance 2015-02-12

Jupiter, Io's shadow, Io, Europa, Ganymede

Jupiter, Io’s shadow, Io, Europa, Ganymede

On the night of February the 12th-13th, 2015 I recorded how Jupiter and its moons have danced. I used a 150/750 Newtonian mounted on a motorized EQ3 mount, a 2x barlow, extension tubes (about 15cm) and a 640×480 @8bit webcam (Scopium) (see my setup here).

From 19:28 to 0:36 (local time, UTC+2) I recorded 234 GiB of raw video (93 files between 1 and 3 GiB) trying to emphasize the key events rather than just record at a given speed – making the animation speed up and slow down accordingly.

Individual frames of the animation are each a result of stacking the best 185 frames of each video (Registax 6). These results have been aligned with PIPP then touched up with IrfanView’s batch processor. Since three setups have been used, the resulting frames had to be resized and rotated to match up in the final output.

Due to a minor hardware failure and/or equipment change (adding an extension tube) recording had to be stopped – out of the 84, 6 frames have been generated using recorded data to fill in these gaps (by derotating Jupiter’s disk and manually adding the moons). I also dropped frames so frame numbering is not incremental.

These are the events I captured

  • Io transiting in front of Jupiter, casting a shadow on the disk (solar eclipse on Jupiter) (frames no. 1-10)
  • Io (partially?) occults Europa (frames no. 18, 19)
  • Europa gets behind Jupiter (frame no. 32)
  • Io (partially?) occults Ganymede (around frame no. 64)
  • Part of Ganymede gets into Io’s shadow (solar eclipse on Ganymede) (frame no. 73)
  • Europa comes out from behind Jupiter but it is still invisible. Then comes out of Jupiter’s shadow (end of a solar eclipse on Europa)
Io's shadow on Ganymede (rendered in 2016 from the original data)

Io’s shadow on Ganymede (rendered in 2016 from the original data)

A solar eclipse on Ganymede

A solar eclipse on Ganymede

 


My(?) Social Network

Me, looking at how me and my friends are connected. Only 284 people

Me, looking at how me and my friends are connected. Only 284 people, but 4052 lines

We tend to call the collective of our friends a network. A social network. We tend to go networking – meeting people. What does my social network mean? I investigated a bit.

For some years it seemed debatable whether social networking sites were private or public space. One might have argued „I am among friends and only friends (those I accepted and they have accepted me) so it is a private matter whatever I do.” Now there is at least one case in Romania when the court ruled that one’s social networking profile is public space and all laws are applicable as such.

This issue made me wonder how private or public is my (or anybody’s) profile depending on the privacy settings applied. So I checked it out and tried to find some other interesting stuff too.

Results in short
I have 283 friends (in a technical sense). My friends have friends anywhere from a few dozen to close to the facebook limit (5000). The count of my friends’ friends is 131,338 individual profiles – so much for the privacy provided by the setting called „friends of friends”. If all my friends who are friends of eachother’s shook hands, that meant 4,052 handshakes. The number of people who are potential audience may easily dwarf that of a regional newspaper and is comparable to the reach of nationwide media products in spite of the seemingly limiting privacy settings of a particular post. (tovább…)


Jól kalibrált monitoron mindegyik számnál elkülönülő árnyalat látszik. Ha mégsem látszanak, akkor a megjelenített képek színhiányosan rajzolódnak ki. A monitort valószínűleg kalibrálni kell.

You should see distinct shades for each number. If those shades are not clearly visible, the displayed pictures will lack accuracy. Your display most likely needs to be calibrated (brightness, gamma, contrast etc.).