Photometry requested for campaign on V1491 Cyg
Active Dates: Nov. 1, 2019 – Nov. 30, 2040
Abstract:
AAVSO observations are requested to support Dr. Dirk Froebrich and colleagues' upcoming observations of V1491 Cyg, a young variable star periodically occulted by material in its circumstellar disk. Observations will be used to map the next occultation (predicted for mid November 2019). They will conduct a [four-week, multi-site], high cadence, multi-wavelengths optical monitoring campaign (in UBVRIHa), using: i) The University of Kent's Beacon Observatory (longitude ~1deg East). ii) Their network of amateur astronomers who work with us as part of our HOYS-CAPS(http://astro.kent.ac.uk/~df/hoyscaps/) citizen science project. iii) Observations with the LCO (in particular the 1m telescope at the McDonald Observatory (longitude ~104deg West)). Given the position of the object (highest right after sunset) we would like to request one set of images in all available filters per observer per night to cover longitudinal gaps and to account for potential bad weather at our other sites.
Justification:
Our light curves indicate a period of about 180 days and occultations lasting 1-2 weeks. These obscurations could be caused by the Hill sphere of an orbiting protoplanet. Multi-wavelength, multi-site observations are required to map the occultations.
Requested Data Types:
Photometry
Targets
| Name | Magnitude | Variability Type | Photometry Notes | Spectroscopy Notes |
|---|---|---|---|---|
| V1491 Cyg | 14.60 | TTS |
Cadence: Custom Precision: 100 |
Not Requested |
Spectroscopy Lines:
No spectroscopy lines provided
Photometry Filters:
U (Johnson), B (Johnson), V (Johnson), R (Cousins), I (Cousins), Other (Please Specify)
Comparison Stars:
Finder charts with comparison stars may be created using the AAVSO Variable Star Plotter (VSP, https://apps.aavso.org/vsp/).
Co-Authorship
Observers are not eligible for co-authorship.
Additional Observer Input:
Observations: We request CCD or DSLR observations of the target as often as possible and in as many optical filters as are available (one observation per filter per night and observer out of occultation, more frequent coverage near and during occultation). In particular we would like BVRI(RGB) observations, but U and Halpha are welcome as well if the equipment is available and the object can be detected. The brightness of the object outside occultations is: B~16.5-17.0, V~14.9-15.4, R~14.2-14.6, I~13.5-13.9; during the occultations the object will be about 0.8mag fainter in all filters. Thus, all the observations should be deep enough to detect the target star at all states with good signal to noise, as we do not know the exact behaviour of the object during this period (the star is intrinsically variable by +-0.5mag outside the occultations). All images should be dark and flat-field corrected. The field of view should be large enough to ensure a sufficient number of comparison stars is available to perform an accurate relative photometric calibration as well to allow us to estimate any colour terms in the photometry. Please stack individual images taken in the same filter per night for an improved signal to noise before submission, but only if they are taken no further apart than 2hrs. Images taken over a longer duration should be stacked separately. The forum link below is in the Campaigns and Observing Reports forum. There is an additional forum thread for this campaign here: Young Stellar Objects: https://www.aavso.org/v1491-cyg-campaign-2019-01
Additional Submission Location:
Data Submission: Observations should be submitted to the AAVSO International Database. ALSO, as this object is in IC5070, and thus part of our HOYS-CAPS citizen science project, the REDUCED IMAGES should be submitted in FITS format via our web-upload system (http://astro.kent.ac.uk/HOYS-CAPS/). Once they are processed the photometry of all the stars in the images will be available immediately publicly via our web interface. To ensure accurate processing, the FITS header should contain information of the filter used, the total exposure time of the stacked images and the mid-point of the integrations in each stack. In case of any questions please contact the PI at df@star.kent.ac.uk or use the HOYS-CAPS facebook group(https://www.facebook.com/groups/342831266192555/).
Notes:
Principal Investigator: Dr. Dirk Froebrich; Imported Campaign (Alert Notice #684).