Explanations for the BAM600 titles

[Azza449]

Hi everyone,

I have just downloaded the BAM600 list and was looking at each of the columns. I am still very new to astronomy and also all of this lingo haha. So I was just wondering if I could have some help with a few points.

1. Firstly can I get a bit of an explanation for what each of the column titles are/mean? (I understand type and constellation)
2. How would I sort the targets into easiest to hardest?
3. Additionally to the explanation from the first question, what is the 0-23 rating for the ra2k?

Thanks! :)

[middy]

Hi Aaron. Here's what the rest of the columns mean:

Vmag = visual magnitude

SB = Surface brightness. Applies to galaxies. This is the magnitude they appear as in the sky because they are not point sources like stars and are spread out over a small area. If you could scrunch them up into a point source then they would have the equivalent magnitude listed in the Vmag column.

Max/Min = Applies to galaxies and is the size in the sky (max = longest axis, min = shortest axis). Sizes are in arc-minutes (') unless it specifically says arc-seconds (").

PA = ??

Subtype = Spiral, barred, elliptical, etc. (Applies to galaxies)

(RA2k, min, sec) = position on the celestial sphere (equivalent to longitude on the earth). Typically listed as hours (0-23), minutes (0-59), seconds (0-59).

(dec, d, m, s) = position on the celestial sphere (equivalent to latitude on the earth). Listed as +/- degrees (-90 <-> +90), arc-minutes (0-59), arc-seconds (0-59).


Probably a good start for ordering is by visual magnitude from brightest (lowest number) to dimmest (highest number)


Cheers,
Andrew

[Azza449]

Awesome, thankyou heaps Andrew! That is a huge help.

So for visual magnitude, is that referring to how bright stars are?

Thanks,
Aaron

[gaseous]

PA = position angle. Used to describe a secondary star's position relative to the main star in a double star.

[ausastronomer]

Hi Aaron,

Patrick and Andrew have pointed you in the right direction.

As Andrew mentioned sorting by Visual Magnitude is a good place to start. If you've downloaded the Excel Version, keep that as a "clean" copy and save another version as a "working" copy. You can than sort and edit to your hearts content and re save with a descriptive file name. eg. Bam 600 (by magnitude); Bam 600 (by month to observe).

If you can let me know what telescope and eyepieces you have and also where you live (more specific than Australia) and what your sky conditions are, I can then help you refine the list to give you something to work with over the next 6 months. These are all pretty important factors. Over 95% of the targets are very achievable in a 10" telescope and dark skies. Over 60% are achievable in a 6" telescope from dark skies. You will struggle to get 25% of them in a 20" telescope from suburban skies in a heavily populated area. Consequently if you live at Maroubra, my advice would be a lot different than if you lived at Coonabarabran. Also if you live in a city, but plan to travel to a dark site, that is an important factor.

You can also save a version of the Excel Spreadsheet as your "observing log" and enter some comments as you tick the targets off the list.

Cheers
John B

[middy]

Correct, the lower the number, the brighter the star/object.

[Azza449]

Sorry for such a late response everyone, I got really busy studying and honestly forgot to check my post again. Thankyou heaps both Andrew and Patrick, that’s super helpful!



Hi John, thankyou heaps for commenting on this post! I will definitely try and sort out the excel spreadsheet like you have recommend, that sounds like the best way to go. I have only recently (probably a month or just over) bought my first telescope. It is a 8” Dobsonian. I only have the provided eyepieces (so 9mm, 15mm, and superview 2” 30mm). I live just out of Ballarat, Victoria. When checking the clear outside website for where I live it says I have a Bortle scale of 4. However, I have looked into a location that apparently is a Bortle scale of 2 which I would use as my dark skies site.

Thankyou heaps again for the information. I can’t describe how helpful that is. If you need anymore information I’d be happy to provide it.

Thanks,
Aaron

[ausastronomer]

Hi Aaron,

You've certainly got good enough conditions to find a lot of targets from home. I have Bortle 4 skies at home and its good enough to make all of the showpiece targets "pop". Like you I have Bortle 2 skies about a 40 minute drive South West.

I've sorted the list into 83 targets for you to start with. I sorted them by best month to observe using August, September and October and then choosing everything brighter than Mag 12. If you send me a PM with your email address I can email it to you. It wouldn't allow me to upload it. You will be able to get a lot of these targets from home and what you can't get from home you will certainly get from your dark site.

Start with these 83 targets and work through them. In a few months I can give you another list of 80 to 100 targets to work on as the sky changes. As time progresses the targets for each month will set earlier in the evening, so I suggest you start with August then move onto September and so on.

Cheers
John B

[gaseous]

I'd like to semi-hijack this thread to say thanks to John once again for this amazing list - still my main observing reference.

[Azza449]

Okay awesome, thankyou for your help! I will send you a PM now.

Agreed Patrick, this is going to be a huge help and guide for me to look at and learn the night sky!!