Mohan-Mishra-Jimenez 1: Newly Discovered Probable Planetary Nebula in Cassiopeia

MoMiJi-1," RAM Nebula" is a newly discovered potential planetary nebula candidate in Cassiopeia Constellation which was founded by Indian Amateur Astronomers named Sankalp Mohan & Utkarsh Mishra(Author) along with Spanish astrophotographer Manuel Jimenez, Our Potential Planetary Nebula candidate was discovered by examining the deep Hydrogen Alpha data shot by manual Jimenez. The Nebula was Photographed by our good friend from UK Peter Goodhew PN-G: 126.0-02.7 Coordinates: 01:16:44.66 +60:00:52.70 Size : 5arcmins Constellation: Cassiopeia Discovered on 10th September 2020

MOMIJI1 Photographed by Peter Goodhew

Location Momiji-1 is located just below the outer silhouettes of the Ghost of Cassiopeia Nebula

The redish region reveals the location of the MoMiJi-1
IC 63 shot by Manuel Jimenez

Nature of the Object Currently, we are not clear about the nature of MoMiJi-1 and we leave that part to the Professionals and the spectrum that will be obtained through larger telescopes, The Potential Discovery is only visible in the Halpha survey, however, even the survey barely manages to show it up unless we pixel peep it. Planetary nebulae (Pne) are created when low/mid mass (M < 8 M_sun) stars go through Post AGB

phase and their outer shell expands. This leaves behind a hot core at several hundreds of thousands of kelvin, which ionizes the surrounding expelled material and forming a PNe. The hot core later becomes a white dwarf(WD) star. PNe may appear similar to HII regions with the difference that the ionizing source has an order of magnitude higher temperature in PNe than the massive O/B stars in the HII regions. As a result PNe can be identified from a distinct optical spectrum with intense high ionization lines. Due to the low density of ejected material, PNe does not have an appreciable continuum as compared to the HII regions. The ratio of [OIII] 5007, [OIII]4959, and H-beta is about 10:3:1 in PNe while the same seldom increases beyond 2:0.6:1 in the HII regions. This is a classical difference between the HII regions and PNe.


Potential Discovery: It is believed that a high fraction (3/4 th ) of PNe in the Milky-way are missed in the present all-sky optical surveys mainly due to two reasons – (i) high extinction in the galactic plane and (ii) dearth of deep spectral-line images of the galactic plane. The emission line (H-alpha. OIII) surveys are better suited to identify missing PNe. H-alpha line imaging surveys such as IPHAS, VPHAS+ etc. regularly identify new PNe and White Dwarf (WD) stars. Due to easy accessibility of observing time on small aperture amateurs telescopes and high potential of discovery, many amateur astronomers also carry out very deep (tens of hours of exposure) H-alpha imaging of the galactic plane using modern CCD cameras at small aperture telescopes and often find new PNe

candidates. They often result into new discoveries when follow-up observations using larger professional telescopes are made. One such PNe candidate is presently identified in a deep H-alpha image of IC 63 nebula region near the galactic coordinates (l=126.1; b=-2.7) in the Cassiopeia region. This candidate has a morphology similar to typical PNe and is located just outside the intense nebulosity of IC 63 (see Fig. 1). The size of the PN candidate is ~5’x5’. A careful search made for this region in the broadband continuum images available from the PanSTARRS survey indicates the presence of a blue star (g-r = -0.2) near the geometrical center of the PN candidate, making this star as the most promising WD candidate associated with the PN (Figs. 2 & 3). All other stars brighter than g=22 mag within the 1’x1’ region of the geometrical center of PN candidate have significant red

colors (see Fig. 3).

Momiji-1 Has a small CSPN which has a magnitude of

magnitude g: 21.5878 magnitude i: 21.9523 magnitude z: 20.5435


Challenges faced during Photographying this object MoMiJi-1 is a very faint candidate and it took us several trials with different astrophotographers to get the signal on this, we contacted several folks who had impressive instruments like the CDK 17 with 16803 CCD, and unfortunately, we couldn't get a good SNR on the nebula, even the 16'' f3.7 that I used remotely failed to get even a hint of it and that's weird, I blame the faulty Badder filters for it We knew that only one guy would be able to do it and that is Mr. Goodhew and yes he did it! he shot the region for more than 30hrs in HaOIII And LRGB, and the nebula was only visible in Halpha and it was very faint so I contacted Marcel for processing these, I tried it myself but didn't quite achieve the result, marcel provided me the uplifted version of this nebula and I later tweaked it a bit up to taste Team MoMi is thankful to Peter Goodhew, Marcel Drechsler, Xavier Strottner, and Dana Patchick who helped in Analysis, Photographying, and Processing of this extremely hard region. The Potential Candidate has been designated on Planetary Nebula net by Pascal Le Du We are extremely proud to tell you that this nebula has been named *RAM Nebula* as we release this in the Month of Diwali.

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