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Monitoring of V2487 Oph requested

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發表於 2016-10-5 06:36:37 | 顯示全部樓層 |閱讀模式
[size=13.3333px]AAVSO Alert Notice 556

[size=13.3333px]October 4, 2016

[size=13.3333px]Monitoring of V2487 Oph requested


[size=13.3333px]Dr. Ashley Pagnotta (Louisiana State University) has requested
[size=13.3333px]AAVSO assistance in monitoring the recurrent nova V2487 Oph in
[size=13.3333px]order to catch and observe its next outburst.

[size=13.3333px]Dr. Pagnotta writes: "V2487 Oph is a recurrent nova that was first
[size=13.3333px]seen to erupt in 1998. During a search of the Harvard College
[size=13.3333px]Observatory plate archives for previous eruptions, we found one
[size=13.3333px]that was recorded in 1900. Based on the speed and magnitude of the
[size=13.3333px]eruption, and the coverage of the archival plates and other
[size=13.3333px]detection sources, we calculated how often V2487 Oph would have to
[size=13.3333px]erupt for us to have actually detected one random outburst on the
[size=13.3333px]plates, which is about once every 18-20 years. (For more, see
[size=13.3333px]http://adsabs.harvard.edu/abs/2009AJ....138.1230P[size=13.3333px]) As we are now
[size=13.3333px]18 years from the previous (1998) eruption, we request regular
[size=13.3333px]AAVSO observations to help us detect the next eruption of V2487 Oph.

[size=13.3333px]"The predicted recurrence time for V2487 Oph is not as precisely
[size=13.3333px]known as that for U Sco, so we are not requesting as intense of an
[size=13.3333px]effort as we did in 2009. Because V2487 Oph is a very fast nova,
[size=13.3333px]however, we are requesting a high cadence [when the outburst
[size=13.3333px]occurs. Previous outbursts have been as bright as V=9.5.]...Once
[size=13.3333px]the eruption has been confirmed (likely by other AAVSO observers,
[size=13.3333px]thanks to the flexibility of your observing programs), we will
[size=13.3333px]notify collaborators and invoke ToO observations to observe the
[size=13.3333px]eruption as comprehensively as possible.

[size=13.3333px]"For the initial detection observations, filter choice is not
[size=13.3333px]critical, although V or Clear would make it slightly easier to
[size=13.3333px]compare to the known quiescence value of V=17.5. If observing in
[size=13.3333px]other filters, it is important to consider color terms before
[size=13.3333px]reporting an early-stage outburst. Following the detection of the
[size=13.3333px]eruption, fast multi-band (if possible) photometry will help us
[size=13.3333px]define the light curve, but any observations would be useful, as
[size=13.3333px]long as V2487 Oph itself is well-detected and not saturated."

[size=13.3333px]Observers are requested to make nightly observations in V or Clear
[size=13.3333px]once or twice a night and report their observations. If V2487 Oph
[size=13.3333px]is brighter than V=17.5, please report the observation(s) to the
[size=13.3333px]AAVSO immediately and switch to multi-color (UBVRI or Sloan
[size=13.3333px]equivalents; Clear if other filters are not available) and high
[size=13.3333px](fast) cadence time-series - exposures of a few minutes, with a
[size=13.3333px]S/N of at least 40-50. The fast effects the PI's are looking for
[size=13.3333px]are on the order of tenths of a magnitude. Report observations as
[size=13.3333px]soon as possible.  

[size=13.3333px]Please continue at high cadence until the decline is underway.
[size=13.3333px]Time-series observations during the decline are not absolutely
[size=13.3333px]essential, but they would be useful to continue to look for flares
[size=13.3333px]and the late time dips that were seen in U Sco around days 41-61.
[size=13.3333px]Nightly observations as before should be continued until the star
[size=13.3333px]has faded to V=17.5, and then for two weeks more.

[size=13.3333px]Coordinates (2000.0): R.A. 17 31 59.81  Dec. -19 13 55.6

[size=13.3333px]Charts with a comparison star sequence for V2487 Oph may be created
[size=13.3333px]using the AAVSO Variable Star Plotter (VSP,[size=13.3333px]https://www.aavso.org/vsp[size=13.3333px]).

[size=13.3333px]Please submit observations to the AAVSO International Database
[size=13.3333px]using the name V2487 OPH.

[size=13.3333px]This campaign is being followed on the AAVSO Observing Campaigns
[size=13.3333px]webpage ([size=13.3333px]https://www.aavso.org/observing-campaigns[size=13.3333px]). A thread has
[size=13.3333px]been created on the Campaigns and Observation Reports forum at
[size=13.3333px]([size=13.3333px]https://www.aavso.org/content/V2487-oph-observing-campaign[size=13.3333px]).


[size=13.3333px]This AAVSO Alert Notice was compiled by Elizabeth O. Waagen.

[size=13.3333px]----------------------------------
[size=13.3333px]SUBMIT OBSERVATIONS TO THE AAVSO

[size=13.3333px]Information on submitting observations to the AAVSO may be found at:
[size=13.3333px]https://www.aavso.org/webobs

[size=13.3333px]ALERT NOTICE ARCHIVE AND SUBSCRIPTION INFORMATION

[size=13.3333px]An Alert Notice archive is available at the following URL:
[size=13.3333px]https://www.aavso.org/alert-notice-archive

[size=13.3333px]Subscribing and Unsubscribing may be done at the following URL:
[size=13.3333px]https://www.aavso.org/observation-notification#alertnotices

[size=13.3333px]-------------------------------------------------
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