Deep Sky Object in Autumn
Around NGC246(Planetary Nebula in Cetus)


Date & Time: Dec 8 2018, from 21:46 to 22:32 JST(+0900)
Composed 10 shots with 5 minutes exposed
Optical: Meade 25cm(10") Schmidt-Cassegrain with conversion lens (f=1600mm, F6.3)
with BaaderPlanetarium Moon&Skyglow filter
Auto-guided with Meade LX200 Equatorial & Pictor 201XT
Digital Camera: Nikon D810A
Location: Ooizumi, Hokuto city, Yamanashi pref.

Camera Settings: Recording Format...14bit CCD-RAW, converted to 16bit TIFF(4080×4080)
Device Size...20×20mm
Sensitivity...ISO4000, White Balance...Daylight


NGC246 / Planetary Nebula, type IIIa
R.A.00h 47m 0.0s (2000.0)
Dec.-11° 53' 00" (2000.0)
Apparent Size4.0×2.5'
Real Size1.73×1.52 light yrs.
Magnitude8.5
Distance1500 light yrs.
NGC246 is a very dimmed planetary nebula at about 6 degrees north of beta Ceti marking a tail of Cetus. You need high magnifying power over 100 to appreciate the nebula with telescopes because it has very small diameter like many other planetary nebulae. And the nebula has very low surface brightness, so you need very conditioned dark sky to enjoy the complicated structure of NGC246. The nebula may give us an impression like very dimmed Helix Nebula (NGC7293), has a central dwarf star with 12th magnitude. And you can detect a fine galaxy of NGC255 just north of NGC246.



NGC40
NGC281

Copyright(c) 2019 by Naoyuki Kurita, All rights reserved.
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