Observations 27-10-2010 eridanus

[Lismore Bloke]

Hi all, the first report for a while. I didn't keep any notes for the first sweep around with the Argo. This is only a start as I’m still getting used to the Argo, trying to minimise positional errors. Notes are a bit scanty, quickly jotted down.The celestial river is a good hunting ground for galaxies. If the weather gods are kind I will be back looking for more. Thanks for reading.




NGC 1386 ERIDANUS
RA 03 36 45.42 DEC -35 59 56.7
CLASS Sa, Sy2
SIZE 3.1X1.5
MAG 12.84v 12mm Nagler (125X)

This is a spiral seyfert galaxy, part of the Fornax cluster. I saw a bright concentrated core but averted vision revealed the elongated outer regions.


NGC 1269 – NGC 1291 ERIDANUS
RA 03 36 45.22 DEC -36 15 28.2
CLASS SBa(S)
SIZE 89”x67”
MAG 14.2 12mm Nagler (125X)

Very small, almost stellar core with a suggestion of a oval shaped fainter outer envelope in averted vision. The bright centre revealed this one, normally a magnitude this faint would give me problems. When looking for galaxies I always scan around the FOV, looking for other objects, but also giving averted vision a chance to pick up something that direct vision did not reveal. Now you see it, now you don’t! Concentrated cores and ellipticals are easier to spot than diffuse, face-on spirals. I’m not sure how this one object had two NGC classifications.


NGC 1389 ERIDANUS
RA 03 37 11.7 DEC -35 44 46
CLASS SB0 (5)
SIZE 2.1X1.4
MAG 11.5 17mm Nagler (88x)

Another member of the Fornax cluster, a lenticular galaxy, but just looked like an elliptical. This one was an oval shaped glow with no discernable core. The fainter outer region visible in averted vision.


NGC 1404 ERIDANUS
RA 03 38 51.7 DEC -35 35 36
CLASS E2
SIZE 2.5X2.3
MAG 11.7 17mm Nagler (88x)

This elliptical member of the Fornax cluster was in the same wide field as NGC 1389. It appearance was almost circular. Even illumination.



NGC 1395 ERIDANUS
RA 03 38 29.6 DEC -23 01 40
CLASS E3
SIZE 3.2’X2.5’
MAG 13.2 12mm Nagler (125X)

Small round galaxy with a tiny bright core, averted vision suggested a faint round outer region.


I did log some other galaxies during the session but didn't keep any notes.

[Rob_K]

Good stuff Paul, a great area with so many galaxies to see! :thumbsup:

Cheers -

[The_Cat]

Good stuff Paul.

What size scope did you use.

I find reports like yours very useful for photography in that I don't have to go looking for objects. You see them and tell us about the objects. Saves time for the lazy !!:thumbsup:

Jeremy.

[Paddy]

Some nice observations there Paul. And pretty impressive detail on a Mag 14 galaxy I must say. Looking forward to more.

[pgc hunter]

Great to see you posting again Paul. Yes, face on spirals are notoriously low sfc brightness, from light polluted areas these are a write off.

[Suzy]

Thank you for your report Paul. The Sombrero is the only galaxy I've seen so far, so I enjoy reading galaxy obs. in particular.

[mithrandir]

1269 discovered by John Herschel in 1836 with a 18.7" reflector
1291 discovered by James Dunlop in 1826 with a 9" reflector

There is a slight difference in the details for them, so they probably were not immediately recognised as the same.

I was reading "Early Australian Optical and Radio Observations of Centaurus A (http://www.iceinspace.com.au/forum/showthread.php?t=67329)" by glenc and others. It has some comments about Dunlop's measurements (his observing condiions were not ideal), so it is quite likely that the coords listed for 1291 are a modern revision.

[Lismore Bloke]

Thanks for the comments everyone.

That's an interesting link Andrew. I remember Glen telling me once that Dunlop's measurements were quite often inaccurate, even by the standards of the day. In spite of that he deserved recognition for his discoveries.

[Lismore Bloke]

Hi Jeremy,
Sorry, just catching up with posts. I used the 12" GSO Dobsonian, now fitted with the beaut Argo system. I'm lucky that Eridanus and Fornax lie in the part of the sky where light pollution is lower.