RASC-TC Missing Data - Measuring Double Stars

[@richardwarren1718]

Blake, man I miss you so much. You will always be in the Hall Of Fame of Teachers. ❤🔭🌌🐜

[@moonmonkey9595]

What a wonderful informative resource this is . Thankyou for the talk I also have Bob’s book and find it very informative too currently in the process of finishing up my double star setup unfortunately only a 90mm so will have to factor that in to see what stars I can realistically study and provide measurements and data on as mentioned above the astrometrics (all brands ) are hard to find but well worth the time to hunt one down as a purely visual amateur astronomer this is my ticket into citizen science and giving something (even if minimal) back to science clear skies

[@blakenancarrow5239]

Note! The formula shown and used in this video works for the Celestron/baader planetarium with its 60 divisions on the Linear Scale. Here's a new universal formula which will work with all eyepieces, including the Meade Astrometric, with 50 divisions. ρ = ( rr * t * f * cos( dec ) ) / d where: ρ = separation in arc-seconds rr = rotation rate of the Earth or 15.0411 t = drift time in seconds f = sidereal time factor or 1.0027379 dec = declination of the star, in decimal form d = divisions or ticks on the LS, in decimal form

[@markharris4539]

Hi. Great vid mate. I've been observing doubles for pleasure for a few years now and been thinking of getting an astrometric eyepiece for a while now. After watching your excellent vid, the choice has been made. Thanks. Mark. Southampton. England.

[@blakenancarrow5239]

Meade Astrometric eyepieces may be available from Opticstar in the UK.

[@MountainFisher]

I found a 2x Tele Vue Barlow and a couple Baader Orthoscopic eyepieces quite enough for the smaller dwarf star partners of the main Star.

[@RASCToronto]

IMPORTANT UPDATE! The Meade Astrometric, Celestron Micro Guide, and baader planetarium Micro Guide reticule eyepieces are no longer available new. You may only be able to buy used. In August 2021, baader planetarium posted an "important note" on their product page which is essentially asking people to indicate their expression of interest. If there is significant commitment, they will resume production. See the baader page for more info. www.baader-planetarium.com/en/accessories/optical-accessories/eyepieces/special-eyepieces-guiding-diascope/micro-guide-eyepiece-with-log-pot-illuminator.html And then vote! on behalf of Blake Nancarrow

[@blakenancarrow5239]

The WDS Neglected list has been discontinued but one can still easily find stars in the database that lack recent observations. Or one can review the notes associated with database entries incomplete or inconsistent information.

[@blakenancarrow5239]

rascto.ca/content/missing-data-double-stars I forgot to add the article link! Sheesh.

[@truthseeker7899]

I’m in the Southern Hemisphere in Australia, I’m interested in observing double stars, I managed to piece together a spreadsheet from this presentation I’m wandering will the calculations differ between the Celestron and Meade astrometric eyepieces? Also does the Sidereal time factor change?

[@blakenancarrow5239]

Hello. Answer 1: I think you might have to do some specific calculations for the eyepieces, yes. That's for a couple of reasons. The Celestron (baader) and Meade are different focal lengths. Given the field of view are different sizes, you will get different drift times. But the time you get will determine the scale for your eyepiece. Also, the linear scales between the two are different, one has 50 units and the other has 60. So, again, that may affect your spreadsheet. Answer 2: I do not think the sidereal time will be an issue. You'll simply need your local sidereal time when logging your measurements.

[@blakenancarrow5239]

Clarification of beta Arietis aka Sharatan. At the time I thought the system was a visual binary but my source was incorrect. It is spectroscopic. Sorry for the confusion.