AAVSO Alert Notice 458: Multiwavelength observing campaign on AE Aqr

AAVSO Alert Notice 458

Multiwavelength observing campaign on AE Aqr

May 11, 2012

Dr. Christopher Mauche, Lawrence Livermore National Laboratory,

and colleagues in Spain and Oman have requested AAVSO observations

in support of their upcoming multiwavelength observations of the

novalike intermediate polar cataclysmic variable AE Aqr with the

Swift satellite, the MAGIC (Major Atmospheric Gamma Imaging

Cherenkov) telescope on La Palma, Canary Islands, and telescopes

at other ground-based observatories in Serbia, Crete, and La

Palma. Their goal is to study the extreme high-energy (gamma-ray)

and high-energy (x-ray) behavior of this complex system. AAVSO

observations will be critical to the success of this campaign.

The MAGIC observations are scheduled for 2012 May 16 - June 1 and

(pending approval) June 13 - 19. The table below gives UT times

of MAGIC observations for each date. Swift observations correlated

with the MAGIC times will be carried out each day as well, and

ground-based photometry has been scheduled.

2012 May 16, 3:21-3:58 UT

17, 3:17-4:32

18, 3:13-4:47

19, 3:09-3:53

20, 3:06-3:49

21, 3:02-3:45

22, 2:58-3:41

23, 2:54-3:37

24, 2:50-3:33

25, 2:46-3:29

26, 2:42-3:25

27, 2:38-3:21

28, 2:34-3:17

29, 2:30-3:13

31, 3:28-4:40

2012 June 01, 4:15-4:40 UT

13, 1:31-2:34

14, 1:27-2:10

15, 1:23-2:06

16, 1:19-2:02

17, 1:15-1:59

18, 1:12-1:55

19, 1:08-1:51

B-band photometry is requested during and +/- 1 hour around the

times of the MAGIC observations in order to correlate the

multiwavelength observations of this campaign. To help establish

the context for the B observations during the MAGIC observations,

please begin making nightly B observations of AE Aqr now, and

continue through the end of June 2012. Visual observations and

photometry in other bands are also welcome. Particularly in May,

AAVSO observations are crucial because all but one of the

ground-based observatories doing optical photometry are too far

west to observe AE Aqr at this time.

AE Aqr, classified as (DQ+ELL), is a magnetic system containing

a white dwarf pulsar and a main sequence star; it is an x-ray

source and shows flares in U and B and in U, B, and V. According

to observations in the AAVSO International Database, its range is

approximately V=10.5-12.5; currently it is magnitude V=11.4. Dr.

Mauche and colleagues carried out a successful multiwavelength

campaign on AE Aqr in 2005 (AAVSO Alert Notice 326,

http://www.aavso.org/node/1555/149).

Coordinates: R.A. 20 40 09.16 Dec. -00 52 15.1 (J2000.0)

Charts for AE Aqr may be plotted using the AAVSO Variable Star

Plotter (http://www.aavso.org/vsp). A table of photometry values

for this field is also available there. Photometrists should

use the 12.2 and 12.4 comparison stars.

Please report all observations to the AAVSO International Database

as AE AQR.

This campaign is being followed on the AAVSO Observing Campaigns

page (http://www.aavso.org/observing-campaigns).

This AAVSO Alert Notice was compiled by Elizabeth O. Waagen.

AAVSO Special Notice 279: Request for monitoring of SS Cygni in support of European VLBI radio observations

AAVSO Special Notice 279

7 May 2012:  As mentioned in AAVSO Alert Notice 445 in August 2011 and AAVSO Special Notice #258 in October 2011, Dr. James Miller-Jones (International Centre for Radio Astronomy Research, Curtin University, Perth, Western Australia) and colleagues have a multiwavelength campaign on the dwarf nova SS Cyg underway as a follow-up to their very successful multiwavelength campaign on SS Cyg in 2010 April (see AAVSO Special Notices #204 and 206 and the related information page).

Earlier in this follow-up campaign, thanks to your excellent coverage and immediate notification to Headquarters of SS Cyg's outburst last August, Dr. Miller-Jones and colleagues were able to obtain excellent observations.

They have more time available, however, and want to observe SS Cyg again.

THE NEXT POSSIBLE OBSERVING WINDOW IS 2012 MAY 15-16.

with subsequent 2012 windows of:
June 19-20
September 17-18
October 9-10
November 13-14
December 4-5

Dr. Miller-Jones says, "Ideally we would like to know the state of SS Cyg (particularly whether or not it is going into outburst) a few days before each of these dates, to give us time to alert the schedulers and get on the telescope if appropriate. We would be extremely grateful for any assistance the AAVSO could provide.”

SS Cyg is the class prototype of the dwarf novae, and the brightest dwarf nova in our skies. In quiescence, SS Cyg varies around V=12.0, and will typically reach V=8.0 at maximum, although anomalous weak outbursts are sometimes seen. SS Cyg last went into outburst 2012 March 21 (JD 2456007.6618, 11.6, F. Vohla; 2456007.64028, 11.2, J. Speil; 2455797.9875, 11.2); the outburst was a narrow one, lasting 11 days. The next outburst may occur at any time. Observations brighter than m(vis)=11.0 should be reported as quickly as possible.

Observers are asked to increase their monitoring of SS Cyg at least through December. Please report all observations as soon as is practical. In the event of an outburst, please report your observations as quickly as you can via WebObs, and also notify Dr. Matthew Templeton and Elizabeth Waagen at AAVSO Headquarters (matthewt@aavso.org, eowaagen@aavso.org). Visual magnitude estimates are a fast and effective means of monitoring SS Cyg; CCD observations are also useful, but please reduce your frames and report your data as soon as possible following an observing run. CCD time-series are not specifically required for this project.

Coordinates for SS Cyg:  RA 21:42:42.79  Dec +43:35:09.9  (J2000.0)

Charts for SS Cyg may be plotted using AAVSO VSP: http://www.aavso.org/vsp

This campaign is being followed on the AAVSO Observing Campaigns page. For more information on this project, please see Dr. Miller-Jones' website: http://www.astro.virginia.edu/xrb_jets

 
Please report all observations to the AAVSO International Database promptly using the name "SS CYG".

This AAVSO Special Notice was compiled by Elizabeth O. Waagen.

AAVSO Special Notice 280: HST UV spectroscopy observations of S Dor scheduled

AAVSO Special Notice 280

May 9, 2012: We have been informed by Dr. Noel Richardson, Georgia State University, that the UV spectroscopy observations of S Dor to be made with the Hubble Space Telescope have been scheduled for

2012 MAY 11 from 21:21:55 UT to 23:55:04 UT.

During the 24 hours prior to and following the HST observations, as well as during them, please increase your visual/BVRI (or as many of these filters as you can) coverage from once per night to twice per night. Afterwards, please return to nightly observations until further notice.

The HST observations of the luminous blue variable prototype S Dor are part of the multiwavelength, multisite campaign described in AAVSO Alert Notice 453 (http://www.aavso.org/aavso-alert-notice-453). As mentioned there, the campaign is to study the photosphere of this star. Optical spectroscopy from CTIO and an amateur in Australia have already been obtained successfully. Approval is still pending for near-IR spectroscopy from SOAR and mid-IR photometry from Gemini.

It is important to continue the excellent monitoring you have been carrying out. Your observations are not only very interesting but also necessary to correlate all of the observations and interpret the variability taking place in S Dor. S Dor is particularly interesting at present because its current state allows the deepest look into its photosphere since the 1960s, leading to a better understanding of its stellar and wind properties. To quote Dr. Richardson, "...the types of variability we are really wanting to probe are the long term trends and the decline to optical minimum it is going through."

Visual and photometric observations are requested on a nightly or twice-nightly basis as described above. BVRI photometry would be ideal, but any filter(s) would be very helpful. According to observations in the AAVSO International Database, S Dor has brightened from visual magnitude ~10.4 in February 2012 to its current value of 10.0. Its decline from visual magnitude 9.2 began in 2006, with a more rapid decline starting in early 2010.

Coordinates: RA = 05 18 14.35  Dec = -69 15 01.1 (2000.0)

Charts may be created using VSP (http://www.aavso.org/vsp).

Please submit observations to the AAVSO International Database using the name S DOR.

This campaign is also described on the AAVSO Observing Campaigns page (http://www.aavso.org/observing-campaigns).

Your observations are key to the success of this campaign. If you have been observing S Dor, please continue. If you have not, and if you can observe this far south, please add S Dor to your nightly list. Many thanks!

This AAVSO Special Notice was prepared by Elizabeth O. Waagen.

ALERT! Comet C/2009 P1 Garrad near NGC 2683

Comet C/2009 P1 Garradd as seen from Mayhill, New Mexico at 11:24 pm May 10. The large rectangle in the field of view of T14, the medium rectangle T20 and the small rectangle T05. Click to embiggen.

Between 10 May and 13 May Comet C/2009 P1 Garradd will be close to the magnitude 9.7 Galaxy NGC 2683. Magbitude 13 galaxy IC 2421 will also be close by.

This will be this plucky little comets last significant encounter before it is lost to view in June.

The window of opportunity is relatively small, between astronomical twilight and getting below the telescopes travel range is a mere 3 hours.