1 Attachment(s)
Object of the Week, October 22, 2017 Baade 1
RA 03h 53.607m
DEc +19° 29.65'
Mag 13.9 (P)
Size 39.8 x 38.3 "
Mag C star 17.2
The constellation of Taurus contains 7 planetary nebulae, most of which are stellar and the only well-known one is NGC 1514 near the Perseus border.
It does however contain one intriguing nebula that is off the radar of most amateur observers in Baade 1, also known as PNG 171.3-25.8.
Baade 1 has a curious discovery history. It was first identified as a faint nebula on plates taken with the 40” Bergedorf reflector of the Hamburg
observatory but it was only confirmed to be a planetary nebula in 1935 on plates taken with the 100” Hooker telescope on Mt Wilson by Walter Baade.
It is the only planetary nebula discovery by Baade in our galaxy, he did however discover a number in M31. Baade 1 is to be found about
5 degrees SW of the Pleiades. The nebula itself is annular but does show some signs of interaction with the local interstellar medium and
it has been classified as at the WZO1 stage, which suggests that the interaction is a faint shock in the material left from the AGB wind and
not yet affecting the shape of the planetary nebula itself. The nebula is very prominent in infrared images from the WISE satellite
which suggests it contains a lot of dust. Optically its central star is very faint at about 17th magnitude. The star does however show
very prominently on images taken with the ultraviolet satellite GALEX, which suggests that it is very hot, which would fit with the fact
that it shows the lines of OVI in its spectrum. As is often the case with planetary nebulae the distance to Baade 1 is not well known
but may well be of the order of 3.5 kpc. At this distance the diameter of the nebula would be 0.28 pc. Baade 1 is located pretty
much at the galactic anti-centre position. I found Baade 1 to be a challenge to see visually. Although it has a listed photographic
magnitude of around 13.9 it appears to be fainter than that visually, unusually for a planetary nebula. I have seen it with a
37cm telescope and an OIII filter from a dark sky location and also with the 55cm telescope also with an OIII. However,
on other occasions it was not seen with the same equipment which suggests that both a dark sky and good transparency
are required, particularly from sites with poor skies such as the UK. I have seen observations of this object with telescope
in the 30cm range but perhaps from better observing locations than are usually found in the UK. It is interesting that
Baade 1 does not appear in any of the standard references although it there are observations of it on the web.
Attachment 2719
Give it a Go and Let is know
Owen
22" f/4.2 Obsession UC
15" f/4.2 Obsession UC
