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Landolt Northern Standards Released

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Richard Wagner
Richard Wagner's picture
Landolt Northern Standards Released

I just noticed that Dr Landolt has released his paper on standards at declination +50!!  Woohoo!  I've been waiting with bated breath since I talked about it with him at the fall 2011 AAVSO general meeting.

Unfortunately, the paper is in the Astronomical Journal (Vol. 146, No. 5) which doesn't allow impoverished amateurs to read their articles for free.  And it wasn't released to arxiv.org, my usual haunt.  Is there any way we can get a copy of the paper?  Particularly the tables?  I can read the article at the library if I have to but typing in the tables would be challenging.

Rick Wagner

WCR

Richard Wagner
Richard Wagner's picture
E-mailed Dr landolt

I decided to just go ahead and e-mail Dr Landolt to see if he will e-mail me a copy of the paper and tables.  I'll advise when I hear back.

Rick Wagner

WBY
WBY's picture
Landolt Standard Stars +50 Lat

You know, what we really need is a searchable table on-line. The Only Landolt Catalog I find in Vizier is Landolt 1992, at least I didn't see any of the more recent ones. What about asking Arlo for permission to publish a searchable table of the + 50 Lat stars on AAVSO? Also, what about adding all of the current landolt standards to SeqPlot?

Brad Walter

Richard Wagner
Richard Wagner's picture
Landolt Standard Stars +50 Lat

To make my own searchable list I converted the 2009 list to a spreadsheet (I think by copying and pasting from the pdf of the original paper), then filtered it for appropriate number of observations, magnitudes suitable for my equipment, fields with nice colour ranges, etc.  I then use the spreadsheet to convert it to a table suitable for ingest into my planetarium software.  Now all the stars, plus a goodly selection of Henden 'standards' (and I have a list of Stetson fields that I have yet to work on) all show up in my star charts for easy planning.  Plus I can access the data tables directly from my processing scripts.

Rick Wagner

TCB168
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Landolt Standards

All of the southern and equatorial standards are available in VSP already.

See here

http://www.aavso.org/standard-stars-vsp

 

Terry B

WBY
WBY's picture
Standard stars

Thanks, Terry. I missed that announcement and didn't know they were there. 

Brad Walter, WBY

WBY
WBY's picture
Lndolt + 50 dec standards

Well I bought the paper. How do we get premission to add the table 2 stars to the AAVSO comp data base? Can Arlo give permission or does it have to come from IOP?

It looks like it would be possible to copy the table into a simple space separated text file and then convert to a csv file or something else. In what format and field order would AAVSO require to add to the comp star data base and what fields would have to be added (e.g. AUID)?

Brad Walter, WBY

Richard Wagner
Richard Wagner's picture
Landolt +50 Standards

Wow - bought the paper!  I'm cheap enough that that never even occurred to me.

I have still not heard back from Dr Landolt.  However an unnamed friend at an unnamed institution provided me with a copy of the paper yesterday.  I've converted Table 2 to a spreadsheet and can make it available for those who would like it (in ODF or XLS format.)

After eliminating stars with too few observations, too faint (for me V>13), fields with fewer than 3 stars, fields with restricted colour range, there are relatively few fields left.  However, there are several really good ones including a couple in the evening sky right now.  (I haven't checked the stars for nearby companions yet.)  If I ever get some clear skies I'll get out a shoot them (along with XZ Cet!)

Rick

HQA
HQA's picture
+50 standards

Matt and I are working on importing these standards into VSD.  It is a multistep process, as you need to watch for duplications during the import, and set priorities when collisions occur.  In addition, we have added a new checkbox on the VSP request form for "Standard Field Chart", which requires standard stars to have a special note added to their record.  So don't get too impatient; the Landolt standards will appear.

Arne

WBY
WBY's picture
Landolt +50 standards

Sorry if I sounded impatient. That wasn't the intent. I was trying to get info to see if I could help since I bought the article. 

 

Brad Walter, WBY

Mark Blackford
Mark Blackford's picture
E and F Region standards

Hi Arne,

Are there any plans to add the Cousins standard stars at -45 and -75 Dec to VSD? Chers,

Mark

FRF
FRF's picture
sounds good

Hi Arne,

This sounds good - I mean adding Landont 50+ to VSP.
(Btw where is the 'like' button? ;)

Clear skies,

Robert

HQA
HQA's picture
Cousins standards

Hi Mark,

I don't think the Cousins standards should be in VSP.  The earlier Landolt standards were originally put in because there were groupings where a CCD observer could measure a handful of standards in a single image.  Having the stars in VSD meant that you could get photometry of these stars via VPHOT.  The Cousins stars are all bright and widely scattered; perhaps ideal for PEP all-sky observing, but not for most CCD observing.  I'm happy to add them to Seqplot (they are probably already in the GCPD, which will be added soon).

The primary use of VSP is to generate finding charts for variables.  We extended that a bit with the Landolt standards, and will do so again with the standard clusters, but I'm hesitant to add stars just because they are calibration sources, yet don't belong to some sequence.

Arne

Mark Blackford
Mark Blackford's picture
Cousins standards

Hi Arne,

Thanks for the explanation, I understand your logic. Having the Cousins standards in SeqPlot would be useful. VPHOT isn't likely to be able to handle DSLR RAW images anytime soon so I guess there is no pressing need for the Cousins standards to be included in VSP.

However, for DSLR users in the south the E and F Regions are ideal for determining transformation coefficients. With a 200mm lens I routinely record several dozen standard stars in a single image. Of course the image scale means many are contaminated by close neighbours but typically 15 to 20 are ok to use. So I would argue that the Cousins standard star regions serve the same purpose for DSLR observers as Landolt standards and standard clusters do for CCD observers.

Cheers,

Mark

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