AAVSO International Database

Alert Notice 859: Photometry and spectroscopy requested for bright binaries being observed with CHARA - Revised (backup copy)

Note: The Alert Notice text below has been revised from the original version issued April 18, 2024.  - Elizabeth O. Waagen, April 19, 2024

Observers are also reminded that it is essential to use the comparison and check stars indicated for the photometry target. If they are too far apart to fit into the same field of view as the target, use PEP-style observing, that is, alternate images of variable, comp, and check.

April 22, 2024                                            REVISED VERSION

Alert Notice 841: VY Scl coverage needed now for HST ToO observations (backup copy)

Notes: HST will not be able to observe VY Scl at this time, so the observations have been canceled. However, the data being obtained by you continue to be extremely valuable to the astronomers, and continuing coverage is requested until after VY Scl has returned to its bright state. Thank you!  -  Elizabeth O. Waagen, January 31, 2024

Alert Notice 785: Monitoring of V452 Vul = HD 189733 requested (backup copy)

Notes: Please continue observations at least through the 2024 observing season.  -  Elizabeth O. Waagen, July 2, 2024

HST observations were postponed. Please continue to monitor V452 Vul as instructed below until further notice.  -  Elizabeth O. Waagen, October 25, 2022

July 5, 2022

Alert Notice 750: T CrB photometry and spectroscopy requested for HST and XMM-Newton observations (backup copy)

Note: Ongoing observations of T CrB are extremely important as the eruption predicted for 2024 draws closer. See HERE for more information.  -  Elizabeth O. Waagen, July 5, 2023, July 2, 2024

Please continue to monitor T CrB until further notice.  -  Elizabeth O Waagen, February 9, 2023

Alert Notice 752: Rare Outburst of Recurrent Nova RS Ophiuchi (backup copy)

Notes: Post-outburst observations continue to be valuable and of interest. Please continue to observe RS Oph.  -  Elizabeth O. Waagen, July 2, 2024

Please continue to observe RS Oph, although the 2021 outburst is over. It returned to a fainter magnitude than before the outburst, so ongoing follow-up observations will be very valuable.  -  Elizabeth O. Waagen, April 4, 2022

August 9, 2021

Alert Notice 838: Monitoring requested for 11 dwarf novae in support of HST observations in 2023-2024 (backup copy)

Notes: LL Lyr was not observed in July 2024 due to technical issues with HST, but it may be observed in August so please continue observations. Also, CS Ind is planned to be observed in August 2024, so please observe it. More information on CS Ind's and LL Lyr's schedules will be issued when available. - Elizabeth O. Waagen, August 4, 2024

KZ Gem has been put on hold by HST, and likely won't be observed until next year, if at all.  -  Elizabeth O. Waagen, January 2, 2024

October 26, 2023