View Online

YSO Bulletin
- 1 December 2019 -


This is the first of what I hope will be a regular newsletter featuring all things Young and Stellar and Object-y for the benefit of members of the AAVSO YSO section and other interested parties. Note that at the moment this is purely a personal venture which is currently (19 Nov 2019) not officially sanctioned by AAVSO, but the plan is to have a google group at some stage. I have a mailing list which you are free to be removed from at your request. Simply send me an email at any time and I shall personally remove you from the list - none of this automatic stuff, but personal, handcrafted service! Likewise if you wish to be included (and I hope you do) contact me by the link above.
I plan to include news items, notices of any interesting behaviour, relevant items from the Star Formation Newsletter and so on. But what would be really good would be contributions / questions / answers from subscribers - so don't say you haven't been warned!

The HOYS-CAPS Project

This exciting project may already be known to some of you but I think this is a good place to introduce it.
Along with many other fields of astronomy, this is of course an acronym, and stands for Hunting Outbursting Young Stars with the Centre of Astrophysics and Planetary Sciences which is a project run by Dr. Dirk Froebrich at the University of Kent (UK) actually just 100k down the N.Sea from me! Rather than explain it all here, click on this link to take you to the project's home page, which includes instructions on how to make and submit your observations, which are CCD only although of course there is nothing to stop visual observers from looking at the concerned stars - but in this case simply send your obs to AAVSO as usual. The submission software is not able to process non-CCD data. Please be aware that participants must read the instructions, since they are quite involved and extensive.

The project lists several areas on which participants may concentrate and are conveniently divided by season. Many stars have individual comments to perhaps guide your observational programme. At the moment, there are no far-Southern YSOs covered, but if you look at the Skiff List on the right you will see that Brian has included several stars in such areas as the Rho Oph starforming region and others nearby.

The project aims to observe nearby, young clusters and star forming regions visible from the northern hemisphere to study the variable young stars. The target list currently contains 9 young clusters visible in the winter and 8 targets for the summer. All targets are listed on the main HOYS-CAPS web-page with their central coordinates and a 3-digit number. Additionally there are several GAIA photometric alert targets that we are following up, some of which are very close to one of the winter/summer targets. If you take images then please try to centre your images as close as possible on the provided coordinates for the clusters, so that we will have an as large as possible overlap of the images. Should the project work well with these clusters we will add more in the future.
Observing Strategy:
Based on the experience of the first few seasons, it might be worth if each participant could focus on one or two of the targets. That simplifies the data analysis. But please feel free to observe any of the objects you like. If you have limited time in a particular night, then several filters for one particular target might be the best option.

The Skiff List

Many of you will be familiar with the name of Brian Skiff of the Lowell Observatory, and Brian has expressed interest in the section's doings. As a result he has provided a list of stars he is currently observing. He says "This is CCD photometry in support of mainly near-IR spectroscopy for radial-velocities of T Tauri-type binaries and in search of young planets." He goes on to make the important point that "Many of the stars are what I call "active accretors", so the variations are chaotic, sometimes dramatic (IQ Tau is our exemplar of this); others are farther along in their evolution and are periodic just from spottedness (i.e. rotation), which typically varies in amplitude and morphology from season to season. Many of the active accretors have published rotation periods that are spurious --- whatever periodicity is present is transient and doesn't have anything to do with the rotation of the star (but everything to do with the sampling in the photometry and the duration of the datasets)."

The list
(Stars on the same line are in the same 15' x 15' CCD field)

  • AA Tau (still historically faint)
  • BP Tau
  • CD-30 6530
  • CI Tau, JH 108
  • DF Tau
  • DH Tau, DI Tau, NSV 16026, [HJS91] 507
  • DK Tau
  • DN Tau
  • DQ Tau, DR Tau, Haro 6-37
  • DS Tau
  • FO Tau, FM Tau, CW Tau, V773 Tau
  • GW Ori, BD+11 820, V649 Ori [lambda Ori region]
  • HBC 355, V402 Tau
  • HBC 362
  • HBC 372
  • HBC 425
  • HBC 684 (in Aql, historically faint just now)
  • HII 1136, HII 1215, HII 1275, V1173 Tau [Pleaides]
  • HII 1883 = V660 Tau, HII 2106, HII 2126 [Pleiades]
  • HII 2244 = V664 Tau [Pleiad]
  • HII 2927, HII 2911, HII 3197, V558 Tau [Pleiades]
  • HK Tau, Elias 3-9 (giant), V806 Tau, V928 Tau, FY Tau, FZ Tau
  • HN Tau
  • HO Tau
  • IQ Tau
  • IW Tau
  • LkCa 3
  • LkCa 7
  • LkCa 15
  • RU Lup, IM Lup
  • TWA 3
  • TWA 6 = BX Ant
  • GM Aur, V396 Aur, V397 Aur
  • V827 Tau, V710 Tau, VSS XI-6, XZ Tau, HL Tau
  • V830 Tau
  • V833 Tau
  • V836 Tau
  • V1023 Tau, V892 Tau, CZ Tau, DD Tau
  • V1067 Tau
  • V1069 Tau
  • V1074 Tau
  • V1075 Tau, V826 Tau, V1076 Tau
  • V1077 Tau
  • V1095 Tau, V1096 Tau
  • V1115 Tau
  • vA 351 = V805 Tau [Hyades multiple system]
  • VY Tau

H-H 212 Imaged
Reipurth et al in issue 323 of the Star Formation Newsletter report extensive bow shocks from the huge flow HH212 in Orion. Previously only detected in the near-IR they present a visual image of HH212. The total extent of the flow is estimated at 2 pc and both flows are punctuated by pulsed shock signatures. The parent object, IRAS 05413­010, appears to be accompanied by another IR source 7" away but it remains to be seen if this is another YSO.
©Michael Poxon 2019. Unsubscribe? Email me for removal from our mailing list.