ODYSSEUS VIII. Southern targets in March/April

Affiliation
American Association of Variable Star Observers (AAVSO)
Fri, 02/25/2022 - 20:53

As part of the HST ULLYSES program (see earlier threads for details), the HST is scheduled to obtain UV spectra of a number of accreting T Tauri stars in the coming weeka. It would be helpful to have BVRI photometry for them in order to help interpret the UV spectra. These are southern targets, mostly in the Chamaeleon clouds (declination -78 deg).

The targets are:

EL Cha (RECX 6)     8 42 38.783   -78 54 42.74 (J2000)   V~14.1
    HST schedule:    2 March 2022 3:15 - 3 Mar 2022 07:10  UT

DI Cha (Sz 19)     11 07 20.728  -77 38 07.31 (J2000)    V~10.7  (10.65-10.74)
    HST schedule:    11 - 13 March 2022

SY Cha             10 56 30.388 -77 11 39.40  (J2000)    V~12  (12.2-15p)
    HST schedule:    22 - 25 March 2022

TW Hya  (monitoring target; second epoch)  11 01 51.91 -34 42 17.0  (J2000)  V=10.6-11.3
   HST plan:    30 March 2022 - 15 April 2022   (12 observations)


The EL Cha times are fixed; I'll update the others as the HST schedule firms up.

If you can observe these targets, please obtain digital BVRI photometrystarting at least a week before the start of the HST observations, and continuing through the conclusion of the HST observations.
It is important to get single BVRI sequences each night, but longer sets of data would be useful if they can be obtained simultaneously with the HST observations. There will not be any TESS observations.


Thank you for all the contributions you have made to this program to date.

 

Affiliation
American Association of Variable Star Observers (AAVSO)
EL Cha, DI Cha, SY Cha, TW Hya - Alert Notice 770

AAVSO Alert Notice 770 requests observations in support of HST observations being carried out on 2022 March 2-3 UT and later in March and April on 4 T Tau stars. These targets are part of Dr. Frederick Walter's ULLYSES program. Please see the notice for details and observing instructions.

There are threads for this campaign under the following forums:

- Campaigns and Observing Reports: https://www.aavso.org/odysseus-viii-southern-targets-marchapril-01
- Young Stellar Objects (YSO): https://www.aavso.org/odysseus-viii-southern-targets-marchapril

Please subscribe to these threads if you are participating in the campaign so you can be updated by the astronomers and by HQ. Join in the discussion or ask questions there!

Many thanks, and Good observing,

Elizabeth O. Waagen, AAVSO HQ

Affiliation
American Association of Variable Star Observers (AAVSO)
Updated HST times for TW Hya 3/30 - 4/9

The HST observing schedule for TW Hya is now posted. Times are in UT.

None of these times are good for observers in South America. But please get what you can - at least one set of BVRI observations per night, and we'll piece together what the star is doing. There is no need to observe after the night of April 10.

Start time: 30 Mar 2022 11:21:23               End time: 30 Mar 2022 12:38:05
Start time: 31 Mar 2022 14:20:44               End time: 31 Mar 2022 15:14:10
Start time: 01 Apr 2022 14:09:34               End time: 01 Apr 2022 15:03:00
Start time: 02 Apr 2022 10:47:52               End time: 02 Apr 2022 11:59:04
Start time: 02 Apr 2022 21:54:40               End time: 02 Apr 2022 22:48:06
Start time: 03 Apr 2022 15:25:12               End time: 03 Apr 2022 16:18:38
Start time: 04 Apr 2022 13:36:17               End time: 04 Apr 2022 14:29:43
Start time: 05 Apr 2022 10:14:37               End time: 05 Apr 2022 11:08:03
Start time: 06 Apr 2022 17:59:45               End time: 06 Apr 2022 18:53:11
Start time: 07 Apr 2022 11:27:35               End time: 07 Apr 2022 12:21:01
Start time: 08 Apr 2022 12:51:43               End time: 08 Apr 2022 13:45:09
Start time: 09 Apr 2022 07:54:49               End time: 09 Apr 2022 08:48:15

Thanks for all your work.

Fred

--

Affiliation
American Association of Variable Star Observers (AAVSO)
HST obs of TW Hya - Alert Notice 774

 

AAVSO Alert Notice 774 requests observations in support of HST observations being carried out now on the YSO TW Hya. This target is part of Dr. Frederick Walter's ULLYSES program. Please see the notice for details and observing instructions.

There are threads for this campaign under the following forums:

- Campaigns and Observing Reports: https://www.aavso.org/odysseus-viii-southern-targets-marchapril-01
- Young Stellar Objects (YSO): https://www.aavso.org/odysseus-viii-southern-targets-marchapril

Please subscribe to these threads if you are participating in the campaign so you can be updated by the astronomers and by HQ. Join in the discussion or ask questions there!

Many thanks, and Good observing,

Elizabeth O. Waagen, AAVSO HQ

Affiliation
American Association of Variable Star Observers (AAVSO)
ODYSSEUS 8 update

The TW Hya campaign is formally over, but we are informed that three of the observations failed, and will likely be repeated the week of April 25.

So please keep TW Hya on your target lists. It would be useful to have a continuous record from now through May 2. I will update this forum with the exact dates

of the HST observations when I learn them, but until then please continue to observe TW Hya when possible.

 

We also have two new HST/ULLYSES targets scheduled the week of April 27 (exact dates to be forthcoming).

Sz 103  16 08 30.269 -39 06 11.18 (J2000)   V=11.1 Warning: Sz 103 is 48" west of V866 Sco A/B (V=7.05), and 62" west southwest of V1027 Sco (V=6.6)

SSTc2d J161243.8-381503  16 12 43.750 -38 15 03.08  (J2000)  V=13.44.

If you can observe these targets, please obtain digital BVRI photometry starting about April 21 before the start of the HST observations, and continuing through the conclusion of the HST observations.
It is important to get single BVRI sequences each night, but longer sets of data would be useful if they can be obtained simultaneously with the HST observations. There will not be any TESS observations.


Thank you for all the contributions you have made to this program to date.

 

Affiliation
American Association of Variable Star Observers (AAVSO)
Sz 103

Hi

I observed Sz 103 at the reported position last night and at April 12.59 UT I determined it to be mag 16.36V (with some uncertainty) which is quite a bit fainter than the reported magnitude in the initial post of 11.1V.  

Regards

Andrew

Affiliation
American Association of Variable Star Observers (AAVSO)
SSTc2d J161243.8-381503

Hi

I observed a star at the report position of SSTc2d J161243.8-381503 and at April 12.59 UT determined it to be mag 14.06V.

However both Sz 103 and SSTc2d J161243.8-381503 will need to be entered into VSX if these observations and more are to be uploaded into the AID.

Regards

Andrew

Affiliation
American Association of Variable Star Observers (AAVSO)
Targets to be added to VSX

Hi Andrew,

Thanks for observing the targets! I'll be adding them to VSX today. We had a major power failure at HQ on Monday that I was dealing with Monday and Tuesday. Sorry for the delay!

Good observing,

Elizabeth

 

Affiliation
American Association of Variable Star Observers (AAVSO)
ODYSSEUS VIII: second update (21 April)

Hi all,

I have further updates, and one new target added to the HST/ULLYSES/ODYSSEUS program.

TW Hya: The last 3 HST observations have been scheduled (times are UT):

   Start time: 25 Apr 2022 11:15:55               End time: 25 Apr 2022 12:09:21
   Start time: 26 Apr 2022 09:28:27               End time: 26 Apr 2022 10:21:53
   Start time: 27 Apr 2022 04:31:22               End time: 27 Apr 2022 05:24:48

Please continue observations though these times. If you can, please try to get observations simultaneously with the HST observations. If not, nightly observations to track trends are important. I will be getting spectra from Chile.

SST c2d J161243.8-381503: There will be a single pair of HST observations:
   Start time: 27 Apr 2022 16:00:40                End time: 28 Apr 2022 07:27:30
   Start time: 28 Apr 2022 12:40:04               End time: 28 Apr 2022 15:07:45

Sz 103:
   Start time: 28 Apr 2022 15:50:27               End time: 29 Apr 2022 03:49:03
   Start time: 29 Apr 2022 12:29:54               End time: 29 Apr 2022 16:33:04
   Start time: 30 Apr 2022 03:01:34               End time: 30 Apr 2022 05:17:34
   Start time: 30 Apr 2022 12:20:01               End time: 30 Apr 2022 16:23:10

The new target is:

Sz 129:  15 59 16.471 -41 57 10.30   (J2000)  V=12.0
   Start time: 30 Apr 2022 17:05:54               End time: 01 May 2022 06:39:55
   Start time: 01 May 2022 13:45:20             End time: 01 May 2022 20:57:58

It is important to get single BVRI sequences each night, but longer sets of data would be useful if they can be obtained simultaneously with the HST observations. Remember, there will not be any TESS photometry, so we will construct a high-cadence light curve from lots of individual measurements at different sites. In all cases, there is little point getting lots of data past the end time of the last HST observation, though one point after the HST end time will help us interpolate through the HST window. I intend to get nightly high-dispersion spectra extending through the night after the last HST observations.

Thank you all for the data you are getting and uploading.

Fred
 

Affiliation
Vereniging Voor Sterrenkunde, Werkgroep Veranderlijke Sterren (Belgium) (VVS)
Uploading observations of recent targets

I am uploading observations from last night of the recent targets SZ... and SST...

Josch