How to refer to astronomical objects

[SteveBz]

Hi Guys,

What is the correct way to identify and refer to astronomical objects?  There seem to be a number of catalogues out there, starting with Messier, through NGC going on to HID and Simbad. I want to keep a log on my computer of all my observations and really I'd like a master reference list to work from.

I like things like Lyr 13, but does that also apply to nebulae and galaxies?  What about solar system objects?  To be truly unique, you probably need RA, DEC and datetime.  Even then occultation would ensure a lack of uniqueness.

Please could someone explain what the preferred reference mechanism is for astronomical objects.

Regards

Steve.

[Merlin66]

Different object types, as you are finding have different naming options....

What ever is the easiest name to remember is usually a good starting point. That and the datestamp for the observation plus the instrument/ camera etc. is enough to repeat or compare observations.

For spectroscopy, for instance we prefer a stellar HD number.

[daz]

The usual method is, as you have already alluded to, using one of the main catalogues to reference your object. Of course, the same object will have different designations in different catalogues but if you are using software to record your observations, many of them will cross-reference these for you.

Solar system objects (eg Comets) are allocated references when they are discovered and and their orbit confirmed, and again, your astro-logging software will usually have the capability to record these and update ephemeris tables.

There is not, at least to my knowledge, one master reference list for all objects.... Sounds like an idea for a project though 

[SteveBz]

6 minutes ago, daz said:

The usual method is, as you have already alluded to, using one of the main catalogues to reference your object. Of course, the same object will have different designations in different catalogues but if you are using software to record your observations, many of them will cross-reference these for you.

Solar system objects (eg Comets) are allocated references when they are discovered and and their orbit confirmed, and again, your astro-logging software will usually have the capability to record these and update ephemeris tables.

There is not, at least to my knowledge, one master reference list for all objects.... Sounds like an idea for a project though 

 

7 minutes ago, Merlin66 said:

Different object types, as you are finding have different naming options....

What ever is the easiest name to remember is usually a good starting point. That and the datestamp for the observation plus the instrument/ camera etc. is enough to repeat or compare observations.

For spectroscopy, for instance we prefer a stellar HD number.

So as I improve my setup and technique I amend the python software I use to control and process it.  Really, what I want to be able to do is say "capture this, this and this, turn off the scope and stuff, stack the output and I'll see you in the morning".  The problem is if "This, this and this" come from different catalogues it makes it hard (eg Saturn and M57).

Regards,

Steve

[SteveBz]

11 minutes ago, Merlin66 said:

For spectroscopy, for instance we prefer a stellar HD number.

Does HD number just apply to stars and not galaxies or nebulae?

Steve

[Merlin66]

The Henry Draper (HD) number is only for stars......and then only the brighter stars I think the faintest HD star is around 9 mag....

https://en.wikipedia.org/wiki/Henry_Draper_Catalogue

 

[ronin]

References like Lyr 13, HID, SAO and a few others refer to stars. The first is just something like the 13th brightest star in Lyra. SAO 113271 in reality means littel as does another reference it has of HIP 27989. It is Betelguese by the way.

Whoever made the catalogue up is not going to use a naming/numbering that matches another. If you spent 20 years making a catalogue you are not going to just copy the SAO reference to SBz numbers.

NGC's are objects, non-point so not stars. As are Messier, Caldwell, Herschell and several others.

Not sure of the difference between say Gamma Lyra and Lyr 3, since gamma is the 3rd letter of the Greek alphabet. So at times I suspect the similarities are close.

Back to Beletguese: These are some of the designations for it:

Betelgeuse, α Ori, 58 Ori, HR 2061, BD+7°1055, HD 39801, FK5 224, HIP 27989, SAO 113271, GC 7451, CCDM J05552+0724AP, AAVSO 0549+07

Comets are getting named after the scope they were seen in then a designation number - may be date related, which seems easy as in Pannstars nnnn

Likely have to have a new reference system for asteroids soon (getting to be more and more) so designations could change again. When we could see say 100 it was "easy" now we can likely see 10,000 then whatever was used is going to no longer apply.

[SteveBz]

25 minutes ago, Merlin66 said:

The Henry Draper (HD) number is only for stars......and then only the brighter stars I think the faintest HD star is around 9 mag....

https://en.wikipedia.org/wiki/Henry_Draper_Catalogue

 

So I could at least use HD for guiding, since I would only be guiding from a relatively bright point-like object.

[SteveBz]

20 minutes ago, ronin said:

References like Lyr 13, HID, SAO and a few others refer to stars. The first is just something like the 13th brightest star in Lyra. SAO 113271 in reality means littel as does another reference it has of HIP 27989. It is Betelguese by the way.

Whoever made the catalogue up is not going to use a naming/numbering that matches another. If you spent 20 years making a catalogue you are not going to just copy the SAO reference to SBz numbers.

NGC's are objects, non-point so not stars. As are Messier, Caldwell, Herschell and several others.

Not sure of the difference between say Gamma Lyra and Lyr 3, since gamma is the 3rd letter of the Greek alphabet. So at times I suspect the similarities are close.

Back to Beletguese: These are some of the designations for it:

Betelgeuse, α Ori, 58 Ori, HR 2061, BD+7°1055, HD 39801, FK5 224, HIP 27989, SAO 113271, GC 7451, CCDM J05552+0724AP, AAVSO 0549+07

Comets are getting named after the scope they were seen in then a designation number - may be date related, which seems easy as in Pannstars nnnn

Likely have to have a new reference system for asteroids soon (getting to be more and more) so designations could change again. When we could see say 100 it was "easy" now we can likely see 10,000 then whatever was used is going to no longer apply.

Ok, I understand now why smartphone apps have four or so drop-downs for navigation, it's because of this multiplicity of catalogues.

Thanks for explaining.

Steve.

[SteveBz]

4 hours ago, ronin said:

References like Lyr 13, HID, SAO and a few others refer to stars. The first is just something like the 13th brightest star in Lyra. SAO 113271 in reality means littel as does another reference it has of HIP 27989. It is Betelguese by the way.

Whoever made the catalogue up is not going to use a naming/numbering that matches another. If you spent 20 years making a catalogue you are not going to just copy the SAO reference to SBz numbers.

NGC's are objects, non-point so not stars. As are Messier, Caldwell, Herschell and several others.

Not sure of the difference between say Gamma Lyra and Lyr 3, since gamma is the 3rd letter of the Greek alphabet. So at times I suspect the similarities are close.

Back to Beletguese: These are some of the designations for it:

Betelgeuse, α Ori, 58 Ori, HR 2061, BD+7°1055, HD 39801, FK5 224, HIP 27989, SAO 113271, GC 7451, CCDM J05552+0724AP, AAVSO 0549+07

Comets are getting named after the scope they were seen in then a designation number - may be date related, which seems easy as in Pannstars nnnn

Likely have to have a new reference system for asteroids soon (getting to be more and more) so designations could change again. When we could see say 100 it was "easy" now we can likely see 10,000 then whatever was used is going to no longer apply.

So I could create a single dropdown box, with each index (eg your example for Betelgeuse above), but I would have a lot of duplicate entries.  I'd need to find a way of de-duplicating them.

[billyharris72]

For DSOs, I guess if you wanted to have as consistent a catalogue referencing system as possible then it would make sense to use NGC and IC catalogue references for all the objects that have them, at least as a secondary reference. They don't overlap (IC is effectively an appendix) and they cover enough objects (about 13,000) to keep you busy for a while. Even so, there are still objects not covered by either (asterisms for example are not covered at all).

In reality, people tend to use whatever name is most commonly used, which in practice means the Mesier catalogue reference is usually used for Messier objects (Messier 31 just seems easier to remember than NGC224). Similarly, if you are making an effort to work through the Caldwell Catalogue, the Herschel 400 or the Collinder Catalogue of open clusters its just easier to use those names than the NGC/IC designation when organising your viewing plan.

Billy.

[SteveBz]

1 minute ago, billyharris72 said:

For DSOs, I guess if you wanted to have as consistent a catalogue referencing system as possible then it would make sense to use NGC and IC catalogue references for all the objects that have them, at least as a secondary reference. They don't overlap (IC is effectively an appendix) and they cover enough objects (about 13,000) to keep you busy for a while. Even so, there are still objects not covered by either (asterisms for example are not covered at all).

In reality, people tend to use whatever name is most commonly used, which in practice means the Mesier catalogue reference is usually used for Messier objects (Messier 31 just seems easier to remember than NGC224). Similarly, if you are making an effort to work through the Caldwell Catalogue, the Herschel 400 or the Collinder Catalogue of open clusters its just easier to use those names than the NGC/IC designation when organising your viewing plan.

Billy.

The issue is for me that I'm automating what I do.  If it was just the Messier catalogue, great, but sometimes it's the Moon or Jupiter, sometimes it's M65, M66 and NGC???? (for the Leo tripple) and I'd like to create a single drop-down list with a search capability.

[billyharris72]

I see where you're coming from. If that's the case though, do you need the name to be consistent, or is it just a matter of having a drop down searchable list? You could quite easily download and compile a catalogue with something like: name, object type, ra, Dec that would enable you to find what you want (be it a star or dso) very quickly. I appreciate that this won't work for the solar system objects, but if I had to have a universal reference for everything else i think I'd use celestial coordinates.

Billy.

[SteveBz]

1 minute ago, billyharris72 said:

I see where you're coming from. If that's the case though, do you need the name to be consistent, or is it just a matter of having a drop down searchable list? You could quite easily download and compile a catalogue with something like: name, object type, ra, Dec that would enable you to find what you want (be it a star or dso) very quickly. I appreciate that this won't work for the solar system objects, but if I had to have a universal reference for everything else i think I'd use celestial coordinates.

Billy.

It might be the right way to go.  I was going to have a selection on constellation first and then select within constellation.  Maybe constellation->list_within_constellation.  That might be easier on the eye.  But's it's obvious to me which is right.