Professor Roger Griffin’s unpublished scientific data

The following notice was published in the 2021 December issue of Observatory magazine. It was pre-written by Roger himself in January 2016, though was subsequently slightly edited by us members of his family in light of actual events.

NOTES FROM OBSERVATORIES

R. F. GRIFFIN’S UNPUBLISHED RADIAL-VELOCITY OBSERVATIONS

Readers of this Magazine will be well aware that for many years each issue included an instalment of R. F. Griffin’s series of papers on Spectroscopic Binary Orbits from Photoelectric Radial Velocities. That series is now concluded owing to the lamented demise of its author. He had, however, accumulated a substantial number of radial-velocity observations of other stars, many of which might have featured in his series of papers if only he had lived to write them. Recognizing that he would not personally be in a position to continue the series indefinitely, he arranged that his unpublished observations would become accessible to interested parties. His family is in the process of carrying out his wishes, and additionally arranging to make all his unpublished data available on the Web; accordingly please consult the following webpage which explains the current situation and gives links to data as they become available: [this webpage]. The unpublished observations all exist in manuscript form in card indexes that are destined to reside in the Library of St. John’s College, Cambridge, CB2 1TP, and may be consulted there through the kindness of the Librarian. Those that pertain to spectroscopic binaries that were being actively investigated are also held in computer files that are easy to understand and can form the inputs to one or another of several orbit-solving programmes that deal with single-lined and double-lined systems, and also with triple systems which have one, two, or three measureable components in their spectra. A listing of those files may be obtained from Dr. R. E. M. Griffin at the Dominion Astrophysical Observatory, Victoria, B.C. [email address redacted], who may be willing to instruct interested parties in the application of the orbit-solving programmes to the data files if those parties do not possess their own software for the purpose.

Alzheimers and a global pandemic

Unfortunately, the seemingly effortless handover which Roger foresaw — in which we family members, upon his death, fetched his boxes of card-index cards from his office and handed them to the waiting College Librarian — did not come to pass.

This was because of the cruel double-whammy of Roger’s Alzheimers disease coinciding with a global pandemic.

Indeed, we were asked to begin emptying Roger’s office at the Institute of Astronomy at Cambridge prior to his death, in October 2020 when its desk (and those of other Emeritus staff) was going to be required urgently to achieve Social Distancing for students. Roger never knew that we had done this, but at the time we half-expected to be able to put everything back more-or-less how we’d found it in due course. But his decline was rapid, and he did not live to return to his office.

Following Roger’s death in February 2021, we subsequently sorted through all the contents of his office and removed a significant quantity of them (but left behind a tonne or two of surplus material), that task requiring daily specific permission to gain access to the site and the building, and being completed during May 2021.

The card-index boxes and their contents

We recovered Roger’s 8 beautiful hand-made wooden trays of card-index cards, and have scanned the entirety of their contents. This comprises 6,287 scans, mostly one scan per card although a few cards contain notes on their reverse. We haven’t yet attempted to make further sense of the cards’ contents, but will do so in due course.

Each box of cards is in a separate folder, and each subdivision of cards (where one existed) is represented by a separate PDF file; each card, or each side of each card in the case of double-sided cards, is contained within one ‘page’ within the PDF file.

On Monday 2022 March 21, we handed Roger’s card-index boxes, together with 38 bound volumes of his research and correspondence, plus a few other items, to the Librarian’s staff at St. John’s College, Cambridge, as per Roger’s wishes. They advised that the items are being stored for a few weeks/months pending the usual intake/accessions process, after which they will be at least nominally accessible to interested parties. However, we hope that Roger’s unpublished data themselves will be much more accessible by being published on the web, above, as compared to requiring an in-person visit to a specific building in the city of Cambridge.

P.S. On Wednesday 2022 November 23, I scanned and added to the above Dropbox folder a further tranche of index-cards (173 scanned sides) which had been retrieved from on or in Roger’s office-desk itself (and sequestered in a large unopened box for the past two years). Some of these undoubtedly relate to specific objects which had been receiving Roger’s attention most recently.

Electronic files relating to Spectroscopic Binaries

We also have copies of Roger’s electronic files relating to his Coravel data and his Spectroscopic Binaries, and have published an initial attempt at the relevant portions of these from this page, below.

Please look in folder sb for the raw input-files relating to Roger’s Spectroscopic Binaries. The folder is now also available as a gzipped TAR file, so you can download the whole thing and peruse at your leisure.

Here, in his own words written in January 2016, is a description of the contents of such files:

People who might be interested in the velocities would indeed normally have their own software for running orbit solutions, or would use whatever is available on the web. But all those files in my SB directory would still serve their purposes. There are four lines at the head of each file, and several at the end - the ones after a blank line - that tell the solving routine what to do and set up suitable scales etc for the plot, but otherwise the file consists simply of a set of dates ('Modified Julian dates') and velocities, such as are inevitably needed as input to no-matter-what orbit-solving programme.

Looking at them as if for the first time, I see some things that are additional to the plain list of dates and velocities. As the very first character in a line, there is in some files a '9'. It is there to tell the output to designate the the immediately preceding periastron passage as the zero of the phases; for someone coming to the files for the first time it could just be replaced by a space. (In that case *my* programme will simply take the *first observation* (in place of the one designated with the 9) as being in the first cycle of the orbit (the one with a zero before the decimal point in the 'phase' column of the output. As it stands, my SB sub-directory has the 'out'files as well as the 'in' ones for the same stars, so anyone could see the relationship between them.)

Then there are entries in some lines *after* the numbers for the date and the velocity. The first such entry, which occurs after three blanks following the velocity, is an individual weighting for that velocity - most often a zero for an observation that is to be rejected (or at any rate is not to be used in computing the orbit) although still featuring in the output. Then there is sometimes a code number, in principle of three digits, starting in the eighth column after the end of the velocity number, which specifies the code for the plotting symbol that appears in the plot of the orbit.

A complication that I had not thought to explain to begin with concerning the files is that those same code numbers are used to identify sources of observations which may need to have (a) corrections to their zero-points, and (b) weightings, which otherwise default to unity. For example, if the code 203 appears opposite an observation, as it often does for early ones, then at the end of the file there may be entries such as 203 0.5 and, on a separate line, 203 100.2. In such a line, if the second number is more than 100, it is a weighting, and the actual weight is that number *less* 100, so in the example just mentioned it would mean that all observations coded 203 would be weighted 0.2 in the solution of the orbit. In ones that do *not* start with 100, the number is a zero-point offset, so in the above example it would mean that all observations with code 203 would be adjusted by +0.5 km/s before they were used in the solution of the orbit; and in the output file those velocities would all appear as 0.5 km/s higher than they are listed in the input file.

Exceptionally, what is usually the last observation in a file may be coded 99; that is a spoof observation that has been entered in the input file simply so that the solution calculates what velocity ought to be expected on that date. I just use it sometimes to forecast what the velocity 'ought' to be on a specific future date; it really needs to be deleted from the input file, and it does not in any case appear in the output file unless it corresponds to a *future* date, so it is easily recognisable there.

Sorry about all that! - I think that that pretty well exhausts the catalogue of complications. I suppose I should apologise that the files for the various stars are not absolutely in the best form to use directly, just the list of dates and velocities as they stand, but the fact that I have been obliged to use various different instruments, whose velocity zero-points are not identical, and moreover of course it is desirable to utilise published observations which again my have differing zero-points (and certainly different weightings for best results) are unavoidable complications.

Seeking updates / further information?

I realise that the above material is not yet complete nor as accessible or self-explanatory as we would wish. Please bear with me, and/or get in touch to ask any questions you may have. I wanted to get the material published sooner rather than later, even if not all the metadata and explanatory material were yet provided.

If you wish to contact us, including Dr. R. E. M. Griffin at the DAO, please send us email. Please also feel free to ask for us to notify you by email when this page gets updated.