Report over Paranal visit Aug 28 - Sept 5 - 2007 PMO 02.09.07 After discussion with Kieran several point have gotten clarified: (1) For Period 79 we shall use only Bessel filters for the Calibration plan (as per CfP). For Period 80 we swap to the new filters for U, B, V, keep using the Bessel for R and I. (2) Standard mode for Calibration plan OBs must be low gain, binning 2x2. Low gain means 2.22 and 2.37 e-/adu (for chip 1 and 2). (3) Kieran is happy to use our proposed fields and strategies, but it is not possible to use Stetson stars until the new pipeline arrives (some data-file format issue that was not clear to Kieran but Carlo should know he says). They need to be able to get their current zero-points from our OBs, which means that we need to make sure that unsaturated Landolt stars will be placed on Chip 1 for each evening twilight (this caused me quite a bit of work as detailed below). (4) Kieran has opened a ticket instructing FORS1 observers to observe one low and one high airmass std field during evening twilight, and minimum one additional field during morning twilight. At least one of the evening fields must provide zero-points. Before I left Garching Sabine provided me with her preferred pointings in fields SA95 (RA~04h), SA110 (RA~19h) and SA113 (RA~22h) which covers the nights in Aug-Oct. We have 6 pointings in each of those fields. The 95 and 110 fields are OK with Landolts on chip 1 for all rotations, but for some of the rotations in the 113 field there are none. As long as those are taken together with 110 OBs that is not a problem, but I need to tie them together in pairs then. The real problem, however, is that most of the Landolt stars will saturate in V, R, I if we integrate 10 seconds in 0.8 arcsec seeing. I dont like the usual procedure with defocusing, that works against our concept of many faint stars. For this reason I have done the following: (a) For each pointing I have determined which Landolt stars are in the field, and which of those are on chip 1 for each rotation. For all those standards I have used the ETC to calculate exposure times such that for 0.8 arcsec seeing the total number of electrons recorded in the central 2x2 binned pixel does not exceed 100.000 (= 45.000 ADU) for the "brightest useful" Landolt. "Brightest useful" does not have an objective definition yet, but the brightest I have allowed for now is V=14.23 (in SA113 which is the troublesome field). (b) For the B and U bands the saturation was never an issue, for those bands I have rather used to ETC to compute exposure times that would bring the brightest star up to 100.000 e- (for B) and up to 10.000 e- (for U). (c) I have then created OBs including 2 exposures of V, R and I, one exposure being short enough to provide the unsaturated Landolts for PSO, the other is of default length as computed below. For B and U there is only a single exposure. Each OB has only a single pointing (i.e. no off-sets this time). Ideally, in 24 observing nights we should get all 6 pointings at all 4 rotations, of all 3 fields. I think we need to continue using this strategy (long for us, short for ZPs) until we are able to include the Stetson stars. Seemingly this will not happen until the new pipeline is installed. I also think it is worth while to continue to compute the exact optimal exposure time for each individual pointing as I have done it for the current 72 pointings/rotations. Sabine and myself should be able to complete this task over the next few months when I am back. Below I describe the definition of the OBs for each of the 72 OBs with notes on individual Landolts covered. Before that I note a couple of useful observations on the general strategy that have come to my attention during my work here the past 2 weeks. ------------------------------------------------------------------------ Default exposure times ---------------------- We decided 10 seconds as the default in order to go deep enough and to make sure the shutter time errors are irrelevant. In fact what we ideally want is to get the same errors in all bands. To help us estimate how we get there I first determined the colours of a "typical Landolt std": B-V U-B V-R R-I 0.85 0.38 0.49 0.44 Based on those we would get the same S/N in all bands (using Bessel filters (upper row), and using high for U, B, V and Bessel R, I (lower row)) for those exposure times (in seconds): U B V R I 575.6 40.3 14.5 10.0 16.2 (Bessel only) 338.1 28.3 12.8 10.0 16.2 (high and Bessel) The U is too long, but I do propose that we move in the direction of equalizing the S/N. For this current run I decided to use the following defaults: U B V R I 200.0 20.0 14.0 10.0 16.0 (using Bessel filters only) ------------------------------------------------------------------------ --------------------------- Narrow band flat-field test --------------------------- Kieran was also very positive towards our request to do the narrow band sky-flat vs Rotator angle final test that we have been talking about. After discussion with Wolfram we decided to do steps of 10 deg, i.e. 36 different Rot angles. First night we managed to get the first series of 9 covering rotator angles from 38 deg to 107 deg. I wrote a little script which made a "movie", and from those 9 alone it is immediately clear that one sees a very nice rotating pattern. It looks pretty identical to the pattern I was seeing during my own VM run several years ago, so I think this is a very stable and likely repeatable effect. Next thing I did was to counter-rotate the 9 frames to see if the rotating pattern is stable, pretty much the thing that Nando did. I was at first rather confused because the de-rotation is not fully correcting for the pattern rotation and in fact after a rotation of 45 degrees the patterns are completely out of phase. After about 20 seconds of being somewhat confused I was laughing as I realized that I should have been able to predict this. We have been guessing all the time that this is the result of reflections off some part of the rotating surface. If you rotate a mirror then the reflected beam rotates with the double angle of the mirror rotation. This is exactly what I found :-D Nando, Sabine, the results you have gotten from de-rotation of flats are not the complete story. In fact any pattern you see is likely just a result of incomplete phase coverage of the input sample. I think we need to do this again, but the data-set we have from the last two nights run is going to be fundmental for understanding the effect. Unfortunately the night astronomer tonight did not want to complete the sequence as the visiting astronomer needed the twilight. I hope we get to complete this before I go down on Wednesday. I think there is a single SM night before so we should be able to do it that night. We still lack about 1/3 of a full circle. ------------------------------------------------------------------------ ------------------------------------------ Notes on each pointing for later reference ------------------------------------------ ------------------- SA110_1 and SA110_2 ------------------- Useful Landolts: L1, 362, 360 Too bright Landolts: 364, 365, 266, 361 All 4 rotations will have at least one of the useful stds on chip 1. For U and B the brighter stds will also be useful. Obj V B U R I L1 16.25 18.00 20.95 15.18 14.19 362 15.69 17.02 20.94 14.77 13.89 360 14.62 15.82 16.36 13.91 13.19 ------------ max 14.62 15.82 16.36 13.91 13.19 exp 5.35 20.65 36.53 3.31 3.79 seconds to reach 10^5 using Bessel ---------------------------------- (for U only 10^4 e-) ------------------------------------- SA110_3, SA110_4, SA110_5 and SA110_6 ------------------------------------- Useful Landolts: L1, 362, (273) Too bright Landolts: 364, 365, 266, 361 3 rotations will have at least one of the good stds on chip 1. One rotation will have only 273 which is really too bright in R and I. For U and B the brighter stds will also be useful. Obj V B U R I L1 16.25 18.00 20.95 15.18 14.19 362 15.69 17.02 20.94 14.77 13.89 273 14.69 17.22 18.25 13.18 11.84 ------------ max 14.69 17.02 18.25 13.18 11.84 (rotation with 273) exp 5.71 61.68 159.3 1.69 1.10 seconds to reach 10^5 using Bessel ---------------------------------- (for U only 10^4 e-) max 15.69 17.02 20.94 14.77 13.89 (rotation without 273) exp 14.30 61.68 461.2 7.29 7.21 seconds to reach 10^5 using Bessel ---------------------------------- (for U only 10^4 e-) For the 3 rotations (A, C, D) I will use: U B V R I 200.0 20.0 10.0 7.0 and 10.0 7.0 and 16.0 For the 273 rotation (RotB) I will use: U B V R I 120.0 20.0 5.0 and 14.0 1.6 and 10.0 1.0 and 16.0 ------------------------------------- SA113_1, SA113_2, SA113_3 and SA113_4 ------------------------------------- Useful Landolts: 241, 245 Too bright Landolts: 239 All 4 rotations will have at least one of the useful stds on chip 1. For U and B the brighter std will also be useful. Obj V B U R I 241 14.35 15.69 17.15 13.45 12.66 245 15.67 16.30 16.41 15.27 14.96 239 13.04 13.56 13.61 12.72 12.40 ------------ max 14.35 15.69 16.41 13.45 12.66 exp 4.18 18.33 38.13 2.17 2.33 seconds to reach 10^5 using Bessel ---------------------------------- (for U only 10^4 e-) For all 4 rotations I will use: U B V R I 200.0 15.0 4.0 and 14.0 2.0 and 10.0 2.0 and 16.0 ---------------- SA113_5, SA113_6 ---------------- Useful Landolts: L1, 337 Too bright Landolts: none Rotations A and B will have both stds on chip 1, C and D will have none. Obj V B U R I L1 15.53 16.87 18.05 13.36 12.64 337 14.23 14.75 14.72 13.88 13.55 ------------ max 14.23 14.75 14.72 13.36 12.64 exp 3.77 7.74 8.50 1.99 2.29 seconds to reach 10^5 using Bessel ---------------------------------- (for U only 10^4 e-) For all 4 rotations I will use: U B V R I 85.0 7.0 and 20.0 3.0 and 14.0 2.0 and 10.0 2.0 and 16.0 --------------------- SA95_1 through SA95_6 --------------------- Useful Landolts: 100, 102, 106, 107 (those are in all 6 pointings) in addition 97 is in SA95_2 Too bright Landolts: 98, 101, 105 All 24 pointing/rotations will have at leaset two good stds Obj V B U R I 100 15.63 16.42 16.47 15.09 14.67 102 15.62 16.62 16.78 15.17 14.55 106 15.14 16.39 16.76 14.75 14.24 107 16.28 17.60 18.72 15.33 14.37 ------------ max 15.14 16.42 16.47 14.75 14.24 exp 8.63 35.74 40.14 7.16 9.94 seconds to reach 10^5 using Bessel ---------------------------------- (for U only 10^4 e-) 97 14.82 15.73 16.11 14.30 13.75 98 14.45 15.63 16.72 13.73 13.11 101 12.68 105 13.57 ------------ For all pointings and all rotations I will use: U B V R I 200.0 20.0 8.0 and 14.0 7.0 and 10.0 9.0 and 16.0 ----------------------------------------------------------------------- ----------------------------------------------------------------------- Here is the ticket re New standard fields opened by Kieran: ----------------------------------------------------------------------- Date: Sat, 1 Sep 2007 22:19:44 +0000 (UTC) From: Paranal_AREmail To: pmoller@eso.org Subject: PSO-010830-New-New stds for FORS1 Mime-Version: 1.0 X-Priority: 3 PSO ticket number PSO-010830 has been submitted to the PSO Data Action Request Class: Request / Problem You are in the CC list for this ticket and this email is for your information only. Entry ID : PSO-010830 Email : kobrien@eso.org Status : New First Name : Kieran Last Name : O'Brien Priority : 6: Comment Short Description : New stds for FORS1 Class : Request / Problem Task : Nighttime Support Astronomer Problem Description : 09/01/07 22:19:13 kueyen Hi, in advance of changing the way we do photometric stds with FORS, we would like to run a test on FORS1 in the coming nights. Palle has made a number of OBs for this purpose which can be found in the queue "FORS1 new std". Each field (identified as new-std-bessel-"fieldname") will have a slightly different pointing and rotator angle. The idea is to pick one OB for a given field that is at low airmass and one at high airmass (currently 110 and 113 respectively) and execute these in twilight. Please try to execute them with full AO (note some stars may saturate, this is normal). Please execute one set-up (eg RotA) per night. If you need to do additional stds during the night and none of these are suitable, please use the old procedure. These should give a ZP for chip1 as per usual. Any comments, please update this ticket. Thanks in advance, Kieran & Palle Subtask : Kueyen (UT2) Assignee : Kueyen Nighttime Support cclist : pmoller@eso.org akaufer@eso.org Create Date : 09/01/07 22:19:13 Worklog : Submitter : kueyen Attachment Field : ----------------------------------------------------------------------- ----------------------------------------------------------------------- Various emails during the visit: ----------------------------------------------------------------------- Date: Thu, 30 Aug 2007 15:44:13 +0200 (MEST) From: Palle Moller Subject: Re: FORS1 sky flats and rotator position To: wfreudli@eso.org, smoehler@eso.org Cc: fpatat@eso.org, pmoller@eso.org MIME-Version: 1.0 Content-MD5: hTlBUY/e3xx4sgbGaIlSSQ== Dear all, I am on Paranal. I've talked to Kieran about several things. I also mentioned the work Sabine has been doing on the rotating pattern, and about the test we would like to do using a narrow band filter. He was very positive. He suggests that we do it on fors1, and asked how many rotator angles we would need. We have a chance to do it this run I think, so we should grab it. With evenly spaced (in ROT angle) well planned observations, how many different ROT positions would we need? Please let me know asap and I will try to see if we can get this done quickly. Cheers from Paranal, Palle X-Authentication-Warning: pc011919.hq.eso.org: wfreudli owned process doing -bs Date: Thu, 30 Aug 2007 16:55:36 +0200 (CEST) From: Wolfram Freudling X-X-Sender: wfreudli@pc011919.hq.eso.org To: Palle Moller cc: smoehler@eso.org, fpatat@eso.org Subject: Re: FORS1 sky flats and rotator position MIME-Version: 1.0 judging from Sabine's plots, I would guess that one every 10 degrees (i.e. 36 images) is the absolute minimum for getting a decent view of the the features, but only barely enough to get the counter check with the randomly shuffled angles. So 72 would be better, 144 would be perfect. Wolfram On Thu, 30 Aug 2007, Palle Moller wrote: > Dear all, > I am on Paranal. I've talked to Kieran about several things. I also Date: Thu, 30 Aug 2007 22:04:48 +0200 (MEST) From: Palle Moller Subject: Re: FORS1 sky flats and rotator position To: pmoller@eso.org, wfreudli@eso.org Cc: smoehler@eso.org, fpatat@eso.org MIME-Version: 1.0 Content-MD5: fOeIZM7203eKIOLSft+uSg== WOW, do we really need that many? I had hoped less since they are not randomly shuffled. I think we may be able to get 5-10 in a row at max, so we are talking many twilights then. darn ... -pm Date: Sat, 1 Sep 2007 19:30:51 +0200 (MEST) From: Palle Moller Subject: OBs To: kobrien@eso.org Cc: pmoller@eso.org MIME-Version: 1.0 Content-MD5: kj9SieZSHcX5t5V98KL32w== Hi Kieran, On the subject of Std OBs. I am assuming that the standard 2x2, low gain is what you are using, correct? Also, which filters should be part of the standard sequence? u-high, b-high, v-high are obvious I guess, but then what else? R and I bessel? what about the g-high, is that too special or do you want it in the standard sequence also? Which are you doing at present? Cheers, Palle ........................................................................ Date: Sat, 1 Sep 2007 23:23:13 +0200 (MEST) From: Palle Moller Subject: Re: OBs To: kobrien@eso.org, pmoller@eso.org Cc: pmoller@eso.org MIME-Version: 1.0 Content-MD5: 42AA+mRESYA5sjUJM9KVLQ== Hi Kieran, I've made a batch of OBs optimized for both our purposes. There are 4 OBs at RA 18:42 and 4 at RA 21:40 Both sets should be observable in the evening twilight. It would be great if we could do one of each this evening, just so that I can verify that I got everything done right and that the ETC is giving the right numbers. The duration is 12-14 minutes each. I have exported the 8 OBs, they are here: /diska/users/visas4/p2pp-impex/* I'll start walking up now, will see you in a bit, guess I can hitch a ride on the way :) -pm Date: Sun, 2 Sep 2007 19:43:11 +0200 (MEST) From: Palle Moller Subject: data from last night To: kobrien@eso.org Cc: pmoller@eso.org MIME-Version: 1.0 Content-MD5: sfnU/hllKDGpagOcGzGtwA== Dear Kieran, I have some runs to support, so dont think I'll make it up before you leave. If you read this before you go down could I ask you one thing please. The data we took last night, the rotated flats, I am not sure if you already copied them down to the directory where I can work on them. If you did not, could I ask you please just to do it. That would be great thanx. Question: For the rest of Per79 we use then Bessel only. I assume that we swap to the new filters for Per 80, correct? Which filters will we use then U, B, V high - and then still R, I Bessel ? Cheers, Palle ........................................................................ Date: Sun, 02 Sep 2007 14:55:43 -0400 From: "Kieran O'Brien" User-Agent: Thunderbird 2.0.0.6 (Macintosh/20070728) MIME-Version: 1.0 To: Palle Moller Subject: Re: data from last night Content-Transfer-Encoding: 7bit Hi, Palle Moller wrote: > Dear Kieran, > > I have some runs to support, so dont think I'll make it up > before you leave. If you read this before you go down could > I ask you one thing please. The data we took last night, the > rotated flats, I am not sure if you already copied them down > to the directory where I can work on them. If you did not, could > I ask you please just to do it. That would be great thanx. > I will do it now. > Question: > For the rest of Per79 we use then Bessel only. I assume that we > swap to the new filters for Per 80, correct? > > yes, although both will be in the instrument as part of the standard config > Which filters will we use then > > U, B, V high - and then still R, I Bessel ? > Yes, that is the plan. Cheers, K Date: Sun, 02 Sep 2007 15:07:10 -0400 From: "Kieran O'Brien" User-Agent: Thunderbird 2.0.0.6 (Macintosh/20070728) MIME-Version: 1.0 To: UT2 Science Operations Support CC: Palle Moller Subject: flats for tonight Content-Transfer-Encoding: 7bit Hi, Palle wants to continue with the flats we started. Here's how.... 1/Use the normal twilight flat OB @~16hr 2/ Change the rotator poistion in the preset to the one Palle gives you. 3/ Change the filter to OII+44 4/ Change the number to 50 (just so it doesn't stop) 5/ as the first flat is reading out (i.e. not including the test exposure) ask Lorena to offset the rotator by 10deg 6/ continue with this offsetting during read-out until the sequence is finished, or the exposure time is too long (~30secs). Thanks, Kieran Date: Sun, 2 Sep 2007 21:14:18 +0200 (MEST) From: Palle Moller Subject: Re: flats for tonight To: kueyen@eso.org, kobrien@eso.org Cc: pmoller@eso.org MIME-Version: 1.0 Content-MD5: p31/IDBLscll5qTFmk2QXA== Please note that it is a blue narrow band filter, so we can go on sky somewhat earlier than normal. Waiting too long will cause the exposure times to get very long. Before twilight I'll go through all the data of the two previous nights and make a list of Rot-pos's that we still need. Thanks a lot for helping us with this, Palle > >Hi, > >Palle wants to continue with the flats we started. Here's how.... Date: Mon, 3 Sep 2007 06:40:04 +0200 (MEST) From: Palle Moller Subject: How to derotate a reflection - ? To: smoehler@eso.org, fpatat@eso.org, wfreudli@eso.org Cc: kobrien@eso.org, fprimas@eso.org, pmoller@eso.org MIME-Version: 1.0 Content-MD5: 8bZYhKCnQIG3TkEwpQsT5g== --------------------------------------------------------------------- Dear all, This is just to let you all know that Kieran and myself have been working over the past week on both the new phot Calib plan and on the rotating flat tests. I have been writing on a full report which is linked to our web-page (here is the link): http://www.eso.org/~pmoller/FIZZWIG-FAP/Report_AugSept07 However, today I learned something quite new, so I will send this part of the report directly attached to this email. Nando - this is something you may want to think a bit about. Cheers from Paranal, Palle --------------------------------------------------------------------- --------------------------- Narrow band flat-field test --------------------------- Kieran was very positive towards our request to do the narrow band sky-flat vs Rotator angle final test that we have been talking about. After discussion with Wolfram we decided to do steps of 10 deg, i.e. 36 different Rot angles. First night we managed to get the first series of 9 covering rotator angles from 38 deg to 107 deg. I wrote a little script which made a "movie", and from those 9 alone it is immediately clear that one sees a very nice rotating pattern. It looks pretty identical to the pattern I was seeing during my own VM run several years ago, so I think this is a very stable and likely repeatable effect. Next thing I did was to counter-rotate the 9 frames to see if the rotating pattern is stable, pretty much the thing that Nando did. I was at first rather confused because the de-rotation is not fully correcting for the pattern rotation and in fact after a rotation of 45 degrees the patterns are completely out of phase. After about 20 seconds of being somewhat confused I was laughing as I realized that I should have been able to predict this. We have been guessing all the time that this is the result of reflections off some part of the rotating surface. If you rotate a mirror then the reflected beam rotates with the double pattern speed of the mirror rotation. This is exactly what I found :-D Nando, Sabine, the results you have gotten from de-rotation of flats are not the complete story. In fact any pattern you see is likely just a result of incomplete phase coverage of the input sample. I think we need to do this again, but the data-set we have from the last two nights run is going to be fundmental for understanding the effect. Unfortunately the night astronomer tonight did not want to complete the sequence as the visiting astronomer needed the twilight. I hope we get to complete this before I go down on Wednesday. I think there is a single SM night before so we should be able to do it that night. We still lack about 1/3 of a full circle. ------------------------------------------------------------------------ X-Authentication-Warning: pc011919.hq.eso.org: wfreudli owned process doing -bs Date: Mon, 3 Sep 2007 08:59:34 +0200 (CEST) From: Wolfram Freudling X-X-Sender: wfreudli@pc011919.hq.eso.org To: Palle Moller cc: smoehler@eso.org, fpatat@eso.org, kobrien@eso.org, fprimas@eso.org Subject: Re: How to derotate a reflection - ? MIME-Version: 1.0 Hi Palle, good to hear about the new data. I remember that a long time ago we had a discussion before how fast the pattern rotates, but we concluded it really does rotate with the rotator angle. Otherwise it would be hard to understand why in Nando's plots the finger came out so strongly. In any case, it should be easy enough for Sabine to do the test: Just re-create at least a few of the cases where we see a strong pattern and de-rotate them with 2*rot angle. I hope she can do it when she is back. cheers, Wolfram On Mon, 3 Sep 2007, Palle Moller wrote: > --------------------------------------------------------------------- > Dear all, Date: Mon, 3 Sep 2007 21:37:51 +0200 (MEST) From: Palle Moller Subject: Re: How to derotate a reflection - ? To: pmoller@eso.org, wfreudli@eso.org Cc: smoehler@eso.org, fpatat@eso.org MIME-Version: 1.0 Content-MD5: C8iIupv5V+NO7YnHqLyu6A== > >Hi Palle, > >good to hear about the new data. I remember that a long time ago we had a >discussion before how fast the pattern rotates, but we concluded it really >does rotate with the rotator angle. Otherwise it would be hard to >understand why in Nando's plots the finger came out so strongly. Well, that must have been a discussion between you and Nando then, I was not involved in it. I think it is most likely that reality is much more complex, and that we see a mix of all sorts of reflections and false light entering from different places. It may well be that different components dominate for narrow and broad bands, for blue and red bands. I hope that we can get the remaining angles before I leave, and then I think we should make a movie or similar and look at it carefully and see what we can learn from this before we start jumping to do all sorts of other things. I've never done this de-rotating myself before, but once you do it you realize that there are some free parameters to play with. The patternspeed is one, but the center of rotation is also not obvious. Problem is a bit now that Kieran has left, and without him the current FORS1 observer and the current shift-leader just dont have a great interest in this which is just annoying extra work for them. Without Kieran I have just no way of forcing this through. > >In any case, it should be easy enough for Sabine to do the test: Just Date: Mon, 3 Sep 2007 22:01:31 +0200 (MEST) From: Palle Moller Subject: Activities tonigh? To: shubrig@eso.org Cc: pmoller@eso.org, fors1@eso.org, kobrien@eso.org MIME-Version: 1.0 Content-MD5: Z1a+v3EvmrppgPeZDhV/Pg== Dear Swetlana, As we talked about yesterday evening there are two things I would need to do before I leave on Wednesday. The first is to complete the "rotator angle twilight image test" which should take about 15 minutes starting at sunset. The other is to get started on the new sequence of Photometric Standard fields which we need to make in support of the new pipeline which is being developed. Kieran has sent emails (and opened a ticket, PSO-010830) describing this. Since we could not do it yesterday as the twilight was used by the VA, I would hope that we may be able to do it tonight? Is twilight tonight available for those activities, or do you have other plans? If not tonight, then tomorrow night will be my last chance as I am going down on Wednesday. Please let me know which time is the best for you. Cheers and thanks, Palle ........................................................................ Date: Mon, 3 Sep 2007 11:42:19 +0200 (MEST) To: par-sciops@eso.org From: "Paranal Earthquake Intensity" Subject: Paranal Earthquake Report PARANAL EARTHQUAKE SUMMARY REPORT -------------------------------------------------------------------------------------- Local Time: September 03, 2007 5:40:52 AM UTC Time: 2007/09/03 09:35:16 Risk Level: MEDIUM RISK Richter: 3.563 Epicenter Estimated Distance from Paranal: 80.000 [kms] Paranal Estimated Mercalli Intensity: 4.081 Peak Ground Acceleration: 7.772 [cm/seg2] ------------------------------------------------------------------- 1.- IMPORTANT!! Earthquake Inspection Procedure Start at LOW RISK, that mean Paranal Mercalli Intensity >= 3 2.- Refer to the Document Eartquake Inspection Procedure : http://bscw.pl.eso.org/paranal/bscw/bscw/bscw.cgi/d56371/VLT-PRO-ESO-10000-3237-1-WithAppendixes.pdf This information is stimated using the data capture at the Paranal Earthquake Station Please, correlate this information with the "U. de Chile" Webpage : http://ssn.dgf.uchile.cl Check the sismic wave at: http://odyssey5.pl.eso.org/paranal/engineering/earthquake/quake.htm