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Planetary images from the long weekend

ε Lyrae

Using the N 150/750 on the HEQ5 and the Scopium webcam, I obtained the following frames. Do note that planetary imaging means a technic – many frames, a 1-2 minutes long video of short frames, stacked -, essentilly lucky imaging, so planetary does not mean a target type. Just sayin’ :P

The clouds obscured the occultation of Porrima, so next time.

(tovább…)

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Some Solar System

Sunspot 2661

A few clear hours, in conjunction with my free time, allowed me to take some photos: the Sun, the Moon, Jupiter and Saturn. I still could not find Enceladus. The setup: N150/750 and MC 102/1300 on the HEQ5, Scopium and CCD Labs Q-Guide webcam.

 

(tovább…)

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Days Go By – with a raspberry pi

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Venus- and Sunrise, and other stuff with a Raspberry Pi

I resurrected an old project of mine, a Raspberry Pi with a camera put on a time lapse duty. Right now it is pointed towards East, and takes a picture every minute. I captured several Venus rises (the planet is the morning star right now), Sunrises of course, and some atmospheric optics too.

 

(tovább…)

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Popularity of Deep Sky Objects according to Astrophotographers

Distribution of 2900 photos of 250 objects

I was curious which objects are the most popular targets according to astrophotographers. I used their activity to answer this question.

To find out, I deployed a crawler on two popular Hungarian forums, on asztrofoto.hu and tavcso.hu and harvested all the photos posted from the sites’ beginning till november 2014. Most of the posts had a catalog number in their title, some only a variant of the popular name, but they were heterogenous, as none of the two forums apply strict title/naming conventions. I worked with those that had a recognizable catalog number like M7, Messier 24, NGC 7000, C 38 or something similar – so perhaps many Orion nebula and Lagoon nebula pictures are left out, especially because the most popular objects are easily identifiable without a catalog number. Then I created this table containing around 2900 posts of around 250 objects.

Let’s say popularity is the count an object has been photographed. No wonder the most popular objects are the most prominent Messier and Caldwell objects (like NGC 7000), although the Caldwell catalog”s usage is sparse, the NGC or IC numbers are used instead. I used my DSO to collapse most aliases. Another conclusion is that few objects get a lot of attention and many very little, which is not a surprise either.

(tovább…)

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DSO database on my Csillagtúra

A printscreen of the UI. It uses night mode.

While posting my pictures, and describing the photographed objects, I noticed they are already deeper than most of the shallow catalogs and softwares go. Stellarium has its strengths but also its weaknesses. Astrometry.net’s plate solver also has its limits. The database behind Simbad and the Aladin viewer their website has embedded is great in many ways – on the desktop edition I can point with the mouse, and the pointer’s coordinates get resolved into an object, but no such feature in the web version (I added it, see below). A weakness is that both the web version and the desktop edition are slow to render the sky, I wonder whether they have any caching or the tiles are morphed real time. Anyway,  I wanted something more personal, integrated into my website.

So I made csillagtura.ro/dso. I think I am bad at naming my programs :P. I found this database on github, with more than 200k objects. This database should cover my deeper photographs for a long time. I converted the CSV into an SQL, and extended it with popular names for objects mainly in English, many in Hungarian and some in Romanian. I also added functionalities like search by virtually any aspect of an object, and, very important: cone search around each result, or just a cone search around some coordinates. I also added some virtual sky features: based on UTC time and the visitor’s gps coordinates retrieved from the browser, my program also calculates the objects’ alt-az coordinates.

(tovább…)

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M104 Sombrero Galaxy

On 2017-04-01 I acquired some light from M104 Sombrero Galaxy (Virgo, 7.9m [wiki]), but the raws turned out to be of worse than expected quality so I didn’t invest the usual amount of time into developing the final picture. Equipment: modded HEQ5, N 150/750, Baader MPCC Mark III, Canon 1100D mod. 14 x ISO 3200, 1 min. As smudges, there are also some faint galaxies in the frame:

M 104 – Sombrero Galaxy

(tovább…)

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Extending Stellarium’s Nebulae Images

Stellarium, showing my C38 image

For some reason there are relatively well known objects without a picture in Stellarium‘s database. It is a free project, a fruition of many people’s voluntary work, so no offence. It is well documented how to add new pictures on this page but I found no easy way to be productive at this task. Plus, there are some problems one needs to overcome in order to succeed.

There are extension packs, but I didn’t find C38 (NGC4565) in them. I wanted to include this particular galaxy. I wrote this for version 0.15.

File structure

In the Stellarium folder (in windows, it is c:\program files\stellarium\nebulae\default) there are two kinds of files. The images themselves, and data files, among them the textures.json file. As the name shows, it is a json file easily editable with a text editor. The images should be 2^k (ie 64, 128, 256, 512, 1024…) pixel size, squared, png files. Do note that the square does not mean one has to limit the field of view: it is not the picture file that holds the aspect ratio information, but the coordinates. (tovább…)

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Messier 48

Messier 48

There is nothing interesting about the M48 open cluster, I imaged it as a test of the optics at minimum f – which it kinda failed projecting some ugly halos around almost all the stars. It is a 5.8m DSO in Hydra [wiki]. As a curiosity, this is one of the somewhat debated Messier objects, as there is no notable object at the position marked by Messier. This cluster, in present day also known as NGC 2545, is 5 degrees away from M48’s “original” position. In my picture, the bright star opposite to the cluster is C Hya, accompanied by 1 and 2 Hya and the orange HIP 41316.

(tovább…)

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Markarian’s Chain, through the telescope

Markarian’s Chain

After imaging the galaxy chain with the 200 telelens, at f/2.8, I turned the f/5 telescope to it. Not surprisingly, I registered way less light – also given the lack of guiding at the longer focal limiting the length of the exposures. I remember a discussion on the field with fellow amateur astronomers, about how objects are named, seemingly arbitrarily – however, many of the members of this chain are physically linked, not just a chance alignment, mostly, and it was an astronomer named Markarian who measured their motion. Member galaxies include the two bright ellipticals, M84, M86  and some other NGC members: NGC 4477, NGC 4473, NGC 4461, NGC 4458, NGC 4438 and NGC 4435.

(tovább…)

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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.).