Hi Observers,
I just pulled off from the shelf my binder of charts for the YSO stars. I'd like to suggest 4 stars that would be good beginner stars.
I printed the charts off of VSP on the AAVSO web site.
1. V856 Sco nice bright star mag range 6.8-8.0V print and use a "b" chart. Eta Sco is just off the chart to the left of the 4.9 star.
2. IX Oph 11.8-12.7p range. Print a "b" chart for finder. The 5.1 star is #36 Oph. Then print an "e" that has comp stars down to 13.5.
3. DD Ser 10.1-12.5p Print a "b" chart. The 5.9 star is #5 Aql. Then print a "d" and use this for your observations. It has comp stars to 12.5.
4. OQ Lyr 9.9-10.6p Print a "b" chart. Gamma Lyr is just off bottom of chart about 1 inch left of the FOV+3.0" note. Then print a "c" chart that has comp stars to 11.1 mag. Use the "c" for your observations.
Good Observing!
Chris Stephan
Robert Clyde Observatory
Sebring, Florida USA
My favourite YSO is YZ Cep. Usually she is around 11.4v, with some deep fades down to 13.2v. YZ Cep is easy to find, locates close to eps Cep. To find YZ Cep a "d" chart is enough, in mimuma for observations you can use a modified "e" chart too (it is enough to set the faintest stars to 14.5)
Here you can find my observations of one of these deep fadings:
Hi, Chris, et al,
Just a comment on IX Oph.
Even though it might be an interesting star, it is not a YSO. Its spectral type (Fe), colors and light curve indicates it is a RV Tauri star. So it is actually an OSO ;)) , an "Old Stellar Object", on its way to becoming a white dwarf.
This is the ASAS-3 light curve for it:
http://www.astrouw.edu.pl/cgi-asas/asas_variable/170948-2717.0,asas3,147.5,3803.0000,440,270,0
Best wishes,
Sebastian
Wonderful! Since RV Tauri stars are also a rare group, we just need to call the attention of the LPV Section to observe IX Oph then... :)
Thanks for that. I'll remove IX Oph from the database. With such a mishmash grouping of poorly-studied stars as the GCVS I... type, it's inevitable that many 'I' stars will turn out to be OSO's and not YSO's!
Incidentally... I know Oph is a huge constellation, but it does contain a great many RV stars, doesn't it?
Hi, Mike,
12 RV stars in Ophiuchus out of the 208 RV Tauris known in the galaxy (or at least in VSX). 52 in Sagittarius but 21 come from the OGLE bulge data. 31 in Scorpius.
Ophiuchus shares the 3rd position with Aquila among the constellations with the highest number of RV Tauri stars.
Cheers,
Sebastian
My other favourite YSO is WW Vul. Easy to find, just 1 degree from the "Coathanger" asterizm/cluster. She is a nice UXOR with a range 10.25-12.94V. On the "b" chart the Coathanger is clearly visible, for observing you can use a "d" chart.
Thanks, Sebastian, for pointing out that IX Oph is NOT a YSO star. I'll let Michael know, because it is on his list.
Thanks, Robert Fidrich of Hungary for the comments on WW Vul and YZ Cep. I actually was going to do a post on those next month.
This is why I like the forum. You all can chip in. I love it. In just 3 days we have posts from the UK, Argentina, Hungary, and the USA.
Chris Stephan