The Recovery Project

An international VarAstro offshoot of the UAI Variable Stars Section project.

The team

Primary Investigator: Ivo Peretto (UAI, Variable Star Section, MarSEC observatory, Italy) ricerca@marsec.it
Co-investigators: Mathilde Barbieri (UAI), Filip Walter (CAS Variable Star Section, Stefanik Observatory Prague)
Administrators: Filip Walter

Project focus:

• Selected targets: A growing list of specific variable stars.
• Secondary targets: Interesting objects found within the observed star fields.

Once the photometry is processed, well-covered cases will be published as short papers in RN_AAS to better characterise the stars, and the data will be used to update the AAVSO VSX database as well as VarAstro. The observers are eligible to become co-authors of the resulting papers.

How to participate:

The photometry shall be taken in accordance with each target's instructions and priority described in the targets list below, such as selected comparison stars, cadence, photometry precision. Photometry shall be uploaded via VarAstro website and marked as part of the project. Please report GJD_UTC time standard with timestamp centered within the exposure interval. The data will be assessed for the compliance and feedback will be given to the observers by the coordination team. You are encouraged to upload any variable star photometry acquired during the project sessions and use VarAstro built-in tool to derive minima timings.

Current target:

CzeV4555 and the surrounding field: CzeV4555 (or TIC 335484764) in the Cepheus constellation is an Algolid eclipsing binary star (EA) with apparent magnitude 10.4 (V), period 4.29 days and amplitude of 0.2 mag. From space based photometry it is apparent that one of the components is a pulsating star of some kind. Closer examination of the pulsations as well as the whole system is the goal of this mission.



• Photometry precision: 10 mmag. Smaller instruments shall adjust the exposure length to attain this goal.
• Photometry filters: For instruments up to 20 cm diameter - single filter Johnson V or sloan g'. Instruments 25 cm and larger preferably bi-color photometry using V and B , or r' and g' bands.
• Comparison stars: You are required to use the following comparison stars: TYC 4267-885-1; TYC 4267-2007-1; APASS J221039.89+630801.8
• Observation mode: Continuous follow up is required to cover the whole lightcurve. For the characterisation of the pulsations the inter eclipse lightcurve is needed.