The ground–based spectroscopic observations complementing the COROT ones have continued in December 2007 and January 2008. The log of the observations, a few preliminary results and a look to the future are given

Amado, Pedro

Diaz, D

Huat, Anne-Laure

PORETTI, Ennio

RAINER, Monica

Uytterhoeven, Katrien

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2008Publication Year2023-02-24T08:52:03ZAcceptance in OA@INAFReport on the third run of the ESO Large ProgrammeTitlePORETTI, Ennio; Amado, Pedro; Huat, Anne-Laure; Diaz, D; RAINER, Monica; et al.Authorshttp://hdl.handle.net/20.500.12386/33801Handle3NumberReport on the third run of the ESO Large ProgrammeE. Poretti, P. Amado, A.L. Huat, D. Diaz, M. Rainer, and K. UytterhoevenSeismology Ground-Based Observation Working GroupMarch 6th, 2008; Version 1.0EXECUTIVE SUMMARY. The ground–based spectro-scopic observations complementing the COROT ones have con-tinued in December 2007 and January 2008. The log of the ob-servations, a few preliminary results and a look to the futureare given. The following actions/items are emphasized:1. The FEROS spectroscopic runs on the CoRoT targets ofLRa1 have been characterized by very good weather, asin the past runs; also in this occasion the observers madean excellent work. The spectra have been fully reduced.Long timeseries are available for LPV analysis on HD 49434(γ Dor star) and HD 49330 (Be star);2. the short nights allowed to perform a limited but satisfac-tory filling program;3. it is time to submit a new ESO Proposal. The FEROSinstrument is available for Normal Programmes, but notfor Large Programmes;4. the publication rate must speed up after the availability ofthe space photometric series.1. IntroductionThe ground–based spectroscopic monitoring of the CoRoT tar-gets continued from November 2007 to January 2008. Four siteshave been involved: European Southern Observatory (La Silla,Chile; FEROS@2.2m), Observatoire Haute Provence (France;SOPHIE@1.9m), Calar Alto (Spain; FOCES@2.2m), Mt John(New Zealand; HERCULES@1.0m). As in the previous cases,the goals of this third internal report are to circulate usefulinformation about the ESO observations within the team andto keep the record of the observations. We remind you thatAnne-Laure Huat (Meudon Observatory) and Pedro Amado& Dario Diaz (IAA Granada) have been the observers for theDecember (from 18th to 28th) and January (from 9th to 14th)runs with FEROS, respectively.The main target has been the bright γ Dor variableHD 49434. No other target has been observed at OHP, CalarAlto and Mt. John. On the other hand, the higher perfor-mances ensured by the FEROS instrument allowed us to addanother target for the ESO observations. Two candidates wereavailable, i.e., the Be stars HD 49330 (V =8.95) and HD 50209(V =8.36). Since both are faint, a selection was necessary andthe Be team preferred HD 49330. We remind that HD 50209has been observed one year ago at ESO. The photospheric linesof this Be star are polluted by emission lines formed in the cir-cumstellar environment; moreover, the line profile variationsare weak.We also stress that the Call for Proposals for the ESO Pe-riod 82 clearly states that the 2.2m telescope is not offeredanymore for Large Programmes. A limited amount of nights isavailable for Normal Programmes. We quickly have to find newstrategies (Large Programme with HARPS ? Normal propos-als with FEROS ? ...) to continue our project since proposalshave to be submitted before April 1st, 2008.The next ESO runs are scheduled in the periods 12–22July and August 2–7, 2008. Owing to scheduling constraints,the allocations of our slots has been problematic. Interestedobservers are kindly requested to inform E. Poretti. OHP ob-servations are scheduled in the complementary periods 1–11July and 21–31 July.2. The spectroscopic data of stars observed in Decem-ber 2006 and January 2007The spectra collected at ESO, OHP, and CAHA have beenfully reduced (by M. Rainer, P. Mathias and P. Amado, re-spectively), put in the archive at Merate Observatory and madeavailable upon request to all the CoIs. For each star observedwith FEROS we provide both the calibrated and normalizedmerged spectra.Table 1 updates the list of the observed targets and the(chair)persons at work on the specific stars.3. The ESO runs in December 2007 and January 2008The observations performed at La Silla fully benefitted fromvery good weather. Observations have been secured by Anne-Laure Huat (from December 18th to 28th) and Pedro Amado& Dario Diaz (from January 9th to 14th). Table 2 summarizesthe logs of both runs. The setup was the same as listed in theAppendix of the First Report. We remind that the instrumentmust be set in the Object+Sky mode, the ADC (Atmospheric2Table 1. Targets observed in the framework of ground–basedcomplemetary observations. The responsible(s) of the analysisof the spectroscopic data are also listed.Star Type InvestigatorsHD 49434 γ Dor Mathias and UytterhoevenHD 50209 Be Floquet and HubertHD 49330 Be HubertHD 50747 Am, SB2 DolezHD 50844 δ Sct Mantegazza, Rainer and ZimaHD 50846 Be, EB Fremat and DesmetHD 51106 Am, SB2 DolezHD 292790 F8 PorettiHD 180642 β Cep Briquet and UytterhoevenHD 181231 Be NeinerHD 181555 δ Sct Mantegazza, Rainer and ZimaDispersion Corrector) must be enabled, the binning is 1x1 inthe fast readout and low gain modes. Overheads for focusingare confirmed to be around 10 min plus pointing. HD 34816has been used to better define the blaze function.3.1. Observing cycleThe targets for the ESO observations have been the γ Dor starHD 49434 and the faint Be star HD 49330. The analysis of theprevious observations (January 2007) has suggested that alsoa rapid δ Sct–like variability is excited in HD 49434. Exposuretimes have been set to 240 sec for the bright HD 49434 and to1800 sec for the faint HD 49330.Therefore, we established the following sequence:HD 49434 - HD 49434 - HD 49330 - ...We estimated that the above sequence lasted 45-min, thus en-suring 10–11 cycles per night. Both observers have been veryclever in following the cycle and adapting it to the particularcircumstances. In particular, only HD 49434 was observed atthe beginning and end of nights, when the airmass was toolarge to ensure a good S/N for HD 49330. Moreover, due tothe poor conditions, only HD 49434 was observed on the nightof 26-27 December.3.2. Length of the nightsThe nights of both runs were about 8h–8h20m long, veryclose to the maximum observing time allotted by the lim-itations on the telescope pointing, i.e., 8h40m. We remindthat the observations can be performed from to −4h20m to+4h20m. At these extreme hour angles the airmass of theCoRoT fields is 2.8, i.e., the critical telescope limit. Thenight of 20-21 December started at UT 00h39m≡ST 01h53mand ended at UT 08h57m≡ST 10h12m. The night of 11-12January started at UT 00h30m≡ST 03h10m and ended atUT 08h35m≡ST 11h13m.3.3. Weather statisticsIn total we had 122h at our disposal to observe the COROTfield. Almost one full night (9-10 January) has been lost dueto high humidity. Humidity and strong wind also stopped ob-servations in two nights (25-26 and 26-27 December). More-over, thin clouds disturbed the 18-19 December night and highhumidity, but below the limit, the 12-13 and 13-14 Januarynights.We lost only 13h for meteorological reasons; Anne-Laurealso note that the Full Moon was very close to the CoRoTfield on the Christmas night (24-25 December) and to the blazestar on the next one. Except in the cases of strong wind, duringboth runs the seeing was generally very good (Table 2).3.4. Signal–to–noise ratio evaluationThe S/N values listed in Tab. 2 are the median values of theS/N values in the region 5805–5825 Å. They have been com-puted during the reduction taking into account photon noise,readout noise and flat field correction. These S/N values are1.0–1.5 times greater than the values evaluated by the ob-servers in the 5750-5760 Å and 4902-4910 Å ranges by usingthe MIDAS command @@snr.4. Backup and filling programsThe short nights did not give us the possibility to observe othertargets (filling program) on a fixed basis as we did at the begin-ning and at the end of the nights of the second run. However,a list of some stars was prepared and P. Amado and D. Diazcould observe the brightest at the end of their nights.Be stars (P.I. A.M. Hubert) – All the proposed stars havebeen observed: µ Pic, HD 71510, DR Cha, E Car, f Car, J Vel,ω Car, ρ Car, and V518 Car.B stars (P.I. M. Briquet) – These stars are fainter than theBe ones and hence only a few could be observed: HD 65074,HD 66053, HD 67531, HD 69824, and HD 73568.A backup program (in case of continuous strong wind fromNorth only) has also been prepared, but not used.5. Data reduction, analysis and publication policyWe remind that the proprietary period for the FEROS datacollected in January 2007 has expired. The data are now public.Two papers based on the ground–based observations arein preparation: the first is on the γ Dor star HD 49434 (1stauthor Katrien Uytterhoeven), the second on the β Cep starHD 180642 (1st author Marilyne Briquet). Both papers willnot discuss the CoRoT photometry from space.At the moment, the following statements are valid for otherstars:HD 50844: a common paper discussing ground-based data(high–resolution spectroscopy and multicolour photometry)and space photometry is planned (responsible: E. Poretti).HD 181555: a common paper discussing high–resolutionspectroscopy and space photometry seems the best solution.This δ Sct star is a fast rotator and the merging of photometricand spectroscopic outputs is probably the only way to modelit. The PI of the CoRoT data is Eric Michel.3Table 2. Log of the observing runs (December 2007–January 2008) at ESO with the FEROS@2.2m instrument. The numberof spectra and the S/N range are indicated for every star on each night.Night HD 49434 HD 49330 Seeing NotesV =5.7 V =8.9Exp. Time 240 sec 1800 secDecember 18-19 22 9 ∼0.′′9 Thin clouds at beginning[300-650] [180-285]December 19-20 22 10 0.′′6–1.′′0 First two spectra of HD 49434 low S/N[370-670] [190-280]December 20-21 24 10 ∼0.′′7 Bad seeing at end[300-470] [180-275]December 21-22 24 10 < 1.′′0 Bad seeing at beginning[370-460] [220-290]December 22-23 25 10 <0.′′5–1.′′1[380-507] [240-295]December 23-24 26 10 <0.′′5–1.′′1[390-435] [200-270]December 24-25 26 10 <0.′′5–1.′′5 Full Moon close to the field[375-480] [220-310]December 25-26 12 7 0.′′8–1.′′5 3.5 h lost due to humidity[370-450] [225-280] Full Moon close to the blaze starDecember 26-27 45 – 1.′′0–2.′′0 1.5 h lost due to humidity[100-510]December 27-28 26 10 0.′′7–1.′′5[265-475] [195-280]January 9-10 2 1 After beginning closed due to high humidity[330-340] [144]January 10-11 21 10 0.′′6–1.′′3[280-430] [215-245]January 11-12 21 10 0.′′6–2.′′0[270-365] [155-200]January 12-13 22 10 High humidity, but below the limit[260-330] [165-210]January 13-14 21 10 High humidity, but below the limit[275-380] [170-220]Total 339 127

Report on the third run of the ESO Large Programme

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Report on the third run of the ESO Large Programme

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