Saturday, October 14, 2017

''MESSIER 74'' aka ''Phantom Galaxy''

Messier 74 

Vineri 13 Octombrie a.c. ,am reusit sa vad ,fara cea mai mica umbra de indoiala , galaxia Messier 74 , pe drept cuvant numita ''Phantom Galaxy''. 
Nu am gasit-o prin scanare ,nici prin cautare dupa asterisme stelare scoase din Stellarium.
Singura metoda care a dat rezultate , a fost cea recomandata de catre Sue French.
La Nord -Est de steaua Eta Piscii ,in imediata vecinatate , se afla o stea galbena de 7.45 mv si cu indice de culoare 1.61 ,dupa Stellarium.
Punem aceasta stea in centrul campului vizual si asteptam cinci minute. 
Lasam astrii sa defileze prin campul vizual.
Un prim asterism notabil este o pereche de stele notata cu ''x'' in poza de mai jos.
Urmeaza apoi un triunghi de stele ,notata cu ''y''.
Dupa  cinci minute , am avut galaxia M74 in centrul campului vizual. 
Multumesc Sue !

Nota : dupa familiarizarea cu zona , puteti incepe ''pasajul'' direct de la triunghiul notat cu ''y'' -un asterism foarte vizibil rpin telescop  -  si astfel sa reduceti la jumatate timpul de asteptare.

Obiectul vazut de mine este bestial de slab luminos dar l-am vazut prin aceasta metoda .
In sfarsit !
Am folosit pentru aceasta metoda - numita in engleza ''sweep'' si pe care as traduce-o in romana prin ''pasaj'' - ocularul Erfle Ruski de 15mm si care mi-a oferit un camp vizual efectiv de 44 minute de arc.
Galaxia se vedea la 82x extrem de slab in vedere directa , oarecum mai bine cu vedere periferica. 

Am aplicat atunci recomandarea facuta de Roger N. Clark in cartea sa ''Visual Astronomy of the Deep Sky'' si anume : grosismente mari.
Grosismente mari dar nu la intamplare ci bine alese.
Dupa cum a demonstrat Clark , telescoapele mici arata mai bine obiectele slabe la grosismente mari.
El a folosit 188x pe telescop de 8 inch , eu am avut la indemana grosismentul de 205x ca fiind cel mai apropiat.
Am aplicat grosismentul de 205x ,obtinut cu TeleVue Radian 6mm si atunci am vazut cu adevarat galaxia Messier 74 ca un obiect circular , foarte slab luminos , cu centrul doar cu ceva mai luminos decat restul suprafetei si avand un diametru de 4-5 minute de arc.
Inafara de cateva stelute foarte slabe raspandite in campul de 18 minute de arc , am vazut M74 precedata de o pereche de stele separate de o distanta aproximativ egala cu diametrul galaxiei , stelele sunt orientate pe directia aproximativa Nord-Sud ,cu steaua nordica ceva mai luminoasa.
Galaxia este urmata imediat la Sud - Vest de o stea galbena. 

Am verificat transparenta cerului pe NGC 1435 numita si ''Nebuloasa Merope''.
Urma sa nu ma astept mai tarziu la miracole deoarece ,desi vizibila , nebuloasa din Pleiade nu era mai bine vizibila decat am vazut-o iarna trecuta in dobsonianul de 125mm.

Tentativa de a vedea NGC 1499 ,cunoscuta drept ''California Nebula'' , a fost neconcludenta.
Folosind grosismentul de 49x si filtrul UHC Optolong , am vazut la Nord-Est de steaua HIP 18518 doar filamentul incercuit in poza.
Nebuloasa are o intindere de peste trei grade , este foarte slab luminoasa , dobsonianul de F/6 este nepotrivit pentru asemenea obiecte.
Voi relua tentativa cu luneta de 90x600mm la 24x cu un camp de 130 minute cu ocularul Plossl de 25mm. 

Am incheiat sedinta de observatii cu prima observatie , din acest sezon , a zonei Orion.
Am lasat filtrul UHC pe ocularul de 25mm si astfel am vazut la 49x o nebuloasa M42-43 extraordinara ,asa cum nu am mai vazut.
Am pus ocularul Ruski 15mm pentru 82x si ,spre uimirea mea ,nebulozitatea din NGC 1973- NGC 1975  se vede - slab ce-i drept - dar fara filtru . Mircea

Sunday, August 13, 2017

World Priority : All-mirror TCT of Attila - Telescopul exclusiv catoptric cu optica inclinata al lui Attila

In 2008 my friend Attila Csillag introduced the all-mirror TCT telescope descibed below.
The birth and making of this  telescope was  purely empirical : no theorethical considerations or complex calculus behind it.
It was just something like ...''what if I will use a concave mirror as eyepiece instead of using a lens or a sistem of lenses - unlike to what  anybodye else done in the four centuries of  telescope making since the advent of the telescope''.
When I first mentioned this on the Forum of  ''Antique Telescope Society''  it woke up the interest of Peter Abrahams of the famous site  ''The history of the telescope&the binocular'' :

It seem that Attila is the first telescope maker who devised a telescope in which the image is formed only by reflection.

As I already told , there is not math behind Attila's prototype, no fancy calculations and no insight about the conics providing the best optimized image with this telescope.
But this was the case with many telescope types or prototypes of the past.
For a while the picture of the all-mirror TCT telescope of Attila was present on the '''' site.
But sometime latter  it was erased.
This is why I will repost here my article dedicated to this subject and kindly published by Kevin Brown in the February 2010 issue of the ''Practical Astronomy '' e-magazine.

Well , no wonder , we miss you Kevin Brown wherever you are...

More about ''Practical Astronomy''  and downloadable back issues :

This is the man , Csillag Attila , with some of his home-made telescopes.
Under his right hand there is so-called ''Mimoza/Mimosa '' a 125mm F/5 Newtonian reflector.
Under his left hand we see ''Cusiosul/ The Curious '' a 125mm F/9 Dobsonian telescope.
This telescope was used for hundreds of  outreach sessions ,mainly on the shores of the Mures River.
At left-background we see ''Leviathan'' 200mm F/10 Dobsonian and at right-background is ''Zold Sarkany/ The Green Dragon'' 190mm F/7.7 Dobsonian.
The mirror of the 190mm F/7.7 Dobsonian was made by Beches Gavril , a very talented mirror maker of Timisoara , too early passed away.
The main mirrors of other telescopes were made by Attila together with the mountings.
Do not forget , hanging from the neck is a 20x60mm Russian monocular used to find the star asterisms housing the so-much loved DSO objects and hidden by the urban sky.


Sunday, July 16, 2017

Mix , observatii si ATM / Miscellaneous , observations and ATM

10 April 2017: I observed  the Moon with the 90x600mm refractor  with  magnifications from 24x / Plossl 25mm to 100x / Baader 6mm.
I used Moon & Skyglow filter as well as colored ones : green, yellow, red and blue.
The best results I got were with  the red filter, by which, at 100x, I saw eight or nine ray-craters spread over the Moon's surface.
Remarkable is a radius starting from Tycho, crossing the entire moon to the North-West.
I attach a picture, generally unsuccessful, but in which you can see this amazing radius that "crosses" with all the forms of the lunar relief.

I took note of the position of eight of the ray-craters I remembered, last night I did not have the Moon map with me and I did not took notes.

10 Aprilie 2017 : Am observat Luna cu luneta de 90x600mm la mariri de la 24x/Plossl 25mm pana la 100x/orto Baader 6mm. 
Am folosit filtre ,atat Moon&Skyglow cat si colorate :verde ,galben,rosu si albastru. 
Cele mai bune rezultate le-am obtinut cu filtrul rosu , prin care , la 100x ,am vazut opt sau noua cratere cu raze ,raspandite pe suprafata Lunii. 
Remarcabila este o raza care pornind din Tycho ,strabate intreg discul selenar pana spre limbul nord-vestic. 
Atasez o poza ,in general nereusita dar in care se vede binisor aceasta raza uimitoare care strabate ''cu nepasare'' prin toate formele de relief selenar. 
Am notat pe poza pozitia a opt dintre craterele cu raze despre care mi-am amintit, aseara nu am avut harta selenara la mine si nu am luat notite.

The 90x600mm refractor , the 60x700mm refractor and Fujinon Mariner 7x50mm binocular.

2'' to 1.25'' reduction,University 12.5mm Ortho and Revelation 9mm Plossl.

''Circle T'' Kellner 9mm , orthoscopic 6mm ,Huygens 20mm ,Huygens 9mm and Huygens 6mm oculars.

LV 30mm/2'' ocular ,University 12.5mm Ortho and Revelation Astro 9mm Plossl .

Penelopa 1.5''  DIY pipe -mount , 60x700mm refractor and Lybar chair.

Jupiter Corona on 2 May 2017.

The status of my time tested 125mm F/7 Dobsonian didn't look good.
The worn out legs , ground board and merry-go-round of my 125mm F/7 Dobsonian.
Time for refurbishment !

New ground board with good legs , rubber armored.

The old helicoidal focuser have worn out threads.

Another focuser ,still helicoidal.

 Instead of the merry-go-round I choose teflon on LP record azimuthal bearing.


A new reinforcing ring for the primary mirror end.

Colimation is a must !

Ready for fight ,again!

Moon Corona 3 of May ,2017.
Pics taken with the Nikon Coolpix S3300 compact camera.

 Moon and Jupiter on 5-th of May 2017.

Crepuscular rays in the evening of 27 May 2017.

Work on my home-made 200mm F/6.16 Dobsonian called ''Toleascope''.
The optics -mirrors , oculars ( like Sirius 25mm and Televue Radian 6mm ),6x30mm  finder ,1.25'' colimation laser and the first Ravneberg open-tube mounting were provided by my friend Alin Tolea , a Mecena of Romanian amateur Astronomy.
I started modifications of the mounting to a solid tube ''circus canon'' type to be better adapted for Urban Astronomy.

The rocker , altitude bearings and Stellafane type ground board.

An ocular shelf under development.

Just a mock-up assembly!

The HC-2 ''Kineoptics'' focuser and DIY adapter.
The solid tube is rolled 0.5 mm galvanized steel sheet.

The sky is the limit !