Herbig Ae/Be campaign

Information about outbursts of eruptive stars, Be activity, ...

Herbig Ae/Be campaign

Postby Francisco Campos » Thu Nov 22, 2018 6:53 pm

Hello,

a photometry and spectroscopy campaign of four Herbig Ae/Be stars has been launched by the AAVSO. Interesting for Lhires III spectrographs but lower resolution is also welcome.

Greetings,
Fran

-----------------------------------------------------

November 21, 2018: Dr. Hans Moritz Guenther (MIT; Kavli Institute for Astrophysics and Space Research) and colleagues have requested AAVSO observers' assistance in monitoring several HerbigAeBe stars in support of upcoming observations scheduled with Chandra.

Dr. Guenther writes: "We are going to observe five HerbigAeBe stars (HAeBes). HAeBes are young A or B type stars which are still surrounded by a protoplanetary disk. In that sense, they are similar to their lower mass bretheren, the classical T Tauri Stars. In T Tauri stars, we expect a dynamo similar to our Sun and we do indeed see stellar flares in X-rays which resemble those seen on the Sun or on other active main-sequence stars. In contrast, HAeBes should not have a magnetic dynamo, yet we still see X-rays from many of them. Since we don't understand what's going on, we are going to observe five HAeBe stars with Chandra to test if the strength of the X-ray emission is in some way related to the mass accretion rate.

"...It would be very helpful to get an optical lightcurve and the stellar color for a few days before and after Chandra observations to know if anything unusual happens to these stars, e.g. if they have a super-bright flare or if they suddenly become hidden behind a screen of gas and dust as we saw in e.g. AA Tau or RW Aur in the last few years."

The targets and their tentative scheduling dates are given below in order of scheduling date. The exact dates/times for the Chandra observation may differ by a up to a few days.
VSX Primary Name RA (2000) Dec (2000) Range Date UT
V1307 Ori 06 01 59.99 +16 30 56.7 9.48-9.83 V 2018-11-26
R Mon 06 39 09.96 +08 44 10.2 11-13.8 B 2018-11-26
V1410 Ori 05 31 57.25 +11 17 41.4 9.39-9.73 V 2018-11-27
V346 Ori 05 24 42.80 +01 43 48.3 10.1-10.9 V 2018-11-28

The fifth target, V1295 Aql (20 03 02.51 +05 44 16.7, 7.87-7.89 V), will not be observable from the ground during the scheduled Chandra observations on December 5.

When they become available, the exact Chandra dates will be given in the AAVSO forum thread for this campaign.

One to two BV observations per night are requested, beginning now and continuing for a week after the dates given. Dr. Guenther continues: "I think two bands to get a single color (e.g. B-V) in any system is enough. If any big absorption event e.g. the disk covering the star happens, it will be obvious in any band. It's unlikely (that's presumably why most of these stars don't have regular observations) - but if that happens we would have to know to interpret the Chandra data correctly.

"We would also appreciate H alpha spectroscopy...There are two ways to estimate the mass accretion rate: From the width of the line profile and from the total flux in the line. The first requires a resolution on the order 50 km/s (R about 6000), the second works with lower resolution. Lines are typically at least twice the continuum level, so no exceptional S/N is required."

Instructions on where to send spectroscopy data will be posted on the forum thread for this campaign.

Charts with comparison star sequences for the target stars may be created using the AAVSO Variable Star Plotter (VSP).

Please submit observations to the AAVSO International Database using the names given in the table.

AAVSO Forums: This campaign is the topic of the AAVSO Campaigns and Observing Reports forum thread https://www.aavso.org/herbigaebe-chandra-campaign

and the AAVSO YSO forum thread https://www.aavso.org/herbigaebe-chandra-campaign-0

This AAVSO Alert Notice was compiled by Elizabeth O. Waagen using material provided by Dr. Hans Moritz Guenther.
Francisco Campos
 
Posts: 85
Joined: Sun Nov 29, 2015 10:13 pm

Re: Herbig Ae/Be campaign

Postby David Boyd » Thu Nov 22, 2018 11:04 pm

Here are spectra of V1307 Ori and V1410 Ori taken on 21st November and sent to Dr Guenther today.
David

_v1307ori_20181121_959_D.Boyd_flux.png
_v1307ori_20181121_959_D.Boyd_flux.png (37.17 KiB) Viewed 1507 times

_v1410ori_20181121_914_D.Boyd_flux.png
_v1410ori_20181121_914_D.Boyd_flux.png (45 KiB) Viewed 1507 times
David Boyd
 
Posts: 86
Joined: Wed Dec 11, 2013 5:50 pm

Re: Herbig Ae/Be campaign

Postby Francisco Campos » Sat Nov 24, 2018 7:01 pm

Excellent work, David.

Here are the spectrum of the same stars taken with the DADOS and the 1200 l/mm grating. I'm not sure if they will be useful or not, because the resolution is only medium.

(I don't have the mail where to send the spectrum)

v1307ori_ 20181123_932_FPC.png


v1410ori_ 20181123_982_FPC.png


Greetings,
Fran
Francisco Campos
 
Posts: 85
Joined: Sun Nov 29, 2015 10:13 pm

Re: Herbig Ae/Be campaign

Postby David Boyd » Sun Nov 25, 2018 9:59 am

Hi Fran,

I googled him and found http://space.mit.edu/people/guenther-hans-moritz

David
David Boyd
 
Posts: 86
Joined: Wed Dec 11, 2013 5:50 pm

Re: Herbig Ae/Be campaign

Postby Robin Leadbeater » Sun Nov 25, 2018 10:48 am

Note that except for R Mon, these are also BeSS targets

Robin
LHIRES III #29 ATIK314 ALPY 600/200 ATIK428 Star Analyser 100/200 C11 EQ6
http://www.threehillsobservatory.co.uk
Robin Leadbeater
 
Posts: 1236
Joined: Mon Sep 26, 2011 4:41 pm

Re: Herbig Ae/Be campaign

Postby Francisco Campos » Sun Nov 25, 2018 9:01 pm

David Boyd wrote:Hi Fran,

I googled him and found http://space.mit.edu/people/guenther-hans-moritz

David


Thank you, David!
Fran
Francisco Campos
 
Posts: 85
Joined: Sun Nov 29, 2015 10:13 pm

Re: Herbig Ae/Be campaign

Postby Terry Bohlsen » Tue Nov 27, 2018 10:40 am

Ive also taken 2 spectra using my 3D printed LOSPEC. ~R=5000
Terry
_v1410ori_20181124_499_TBohlsen.png
_v1410ori_20181124_499_TBohlsen.png (8.78 KiB) Viewed 1383 times

_v346ori_20181125_473_TBohlsen.png
_v346ori_20181125_473_TBohlsen.png (9.11 KiB) Viewed 1383 times
Terry Bohlsen
Armidale NSW
Australia
Terry Bohlsen
 
Posts: 136
Joined: Thu Sep 29, 2011 7:40 am

Re: Herbig Ae/Be campaign

Postby Forrest Sims » Thu Nov 29, 2018 6:46 pm

Here is a spectrum of V346 Ori taken with my LISA early morning on 2018-11-29 Arizona time. I was hoping for some exciting emission line like David saw on two of the other campaign targets. Looks like the same Halpha absorption as in Terry’s data from 2018-11-25. Just for curiosity I loaded the V346 Ori fits file into Rspec and checked to see which included Reference spectrum is the best match and was at first surprised to see that F02IV (Blue line profile) looks to be the best match. SIMBAD shows V346 Ori as an A8V. Rspec does not have an A8V for reference but the F02IV immediately follows A7V in the Rspec list. So not such a surprise:)

Woody
Attachments
Rspec Reference check.PNG
Rspec Reference check.PNG (37.87 KiB) Viewed 1326 times
v346ori_20181129_293_Forrest Sims.png
Forrest Sims
 
Posts: 53
Joined: Thu Feb 09, 2017 5:52 pm

Re: Herbig Ae/Be campaign

Postby Robin Leadbeater » Thu Nov 29, 2018 11:39 pm

Interestingly Paolo Berardi's R~5700 resolution spectrum of V346 Ori in BeSS from 2015 does show a narrow H alpha emission line in the broad absorption
http://basebe.obspm.fr/basebe/Spectres_ ... 115552.png
which is absent now in Terry's similar resolution spectrum


Robin
LHIRES III #29 ATIK314 ALPY 600/200 ATIK428 Star Analyser 100/200 C11 EQ6
http://www.threehillsobservatory.co.uk
Robin Leadbeater
 
Posts: 1236
Joined: Mon Sep 26, 2011 4:41 pm

Re: Herbig Ae/Be campaign

Postby David Boyd » Fri Nov 30, 2018 9:53 am

Looking closely at Woody's spectrum of V346 Ori, there is evidence of a small emission feature buried in the H-alpha absorption line, slightly blue-shifted with respect to the absorption line.

David
David Boyd
 
Posts: 86
Joined: Wed Dec 11, 2013 5:50 pm

Next

Return to Outbursts and alerts

Who is online

Users browsing this forum: No registered users and 0 guests

x