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.
Last night I tested an old CCD Labs Q-Guide camera as an autoguider solution. I got the camera from AȚ (thank you :) ) but it came with an unexpacted “semaphore error” message, which rendered it useless. It turned out the firmware was damaged and needed to be reflashed. I found some ideas here, but not the solution itself, which started to come from here was still miles ahead. Worth mentioning the answers given by QiuHY are rather cryptic (tending towards useless), more like from an oracle than a tech guy – and I’m not a believer. A good indicator of just how cryptic: only a month has passed and I already cannot find the best answer, only that it included CySuiteUSB program and a guide in which order to flash what.
So I took some test photos with the Canon 1100Da, N 150/750 on the HEQ5 setup, 4 minutes subs. Ten for the M13 globular cluster, and six for the M57 Ring Nebula. Each at ISO 100 – not that far from the city center (Bortle scale 6-7 if not 8 – better to the north).
M13 test
M57 test
M57, second processing
M57, 3rd processing
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.
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.
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.
A DSO felület éjszakai üzemmódot használ
Észrevettem, miközben közreadáshoz készítettem elő a fotóimat, hogy azok máris mélyebbek, mint amilyen mélyre a legtöbb program megy.
A Stellariumnak megvannak az erős és a gyenge oldalai is. Az astrometry.net keresője (angolul plate solving) szintén korlátok között mozog. A Simbad adatbázis és az Aladin böngésző asztali és web változata egyaránt gazdag kincsesbányája az asztrofotósnak, az asztali változatban a mozgó egér alatti objektumot kikeresi és mutatja például. Ezt a web változat is igazán tudhatná, de nem tudja sajnos (lennebb a javítása). A gyengéje, hogy mintha valós időben készítené elő az égboltot lefedő képeket, így elég lassú. De különben is, valami kézhezállóbbat szerettem volna.
Ezért készült a csillagtura.ro/dso. Azt hiszem, hadilábon állok a programjaim elnevezésével :P. Találtam githubon ezt az adatbázist, bő kétszázezer objektummal. A fotóimhoz jó ideig kellően mély lesz ez az adatbázis. A CSV fájlt SQL adatbázisba emeltem, az objektumok elnevezését pedig jelentősen bővítettem angol és magyar nyelven, illetve behelyeztem néhány román nevet is. Aztán megírtam egy erős keresőfelületet, amely szinte minden szempont szerint ki tudja ásni az adatbázisból a keresett objektumokat. És ami fontos: kúpkeresést is tud, egy objektum vagy egy adott koordináta környezetében. Hozzáadtam még egy virtuális égbolt funkciót: a látogató GPS-e alapján a program az objektumok látszó magasságát és óraszögét is kiszámolja.
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.
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
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.
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…)
