Les alertes AAVSO

[chrismlt]

Salut tous,

 

Le parfum de l'aventure, le suspense, le frisson de l'inconnu ?

Du nouveau sur le coin de ton capteur ?

 

**

 

Je me suis dit que certains d'entre-vous seraient peut-être intéressés à prendre connaissance des alertes AAVSO.

 

Autant d'occasions de mettre le pied à l'étrier de la photométrie, d'avoir des contacts directs avec des chercheurs qui cherchent ... que d'initier la discussion de ce côté ci de l'Atlantique. Voire de coordonner des observations.

 

C

 

 

Eclipse de l'étoile triple b Per, 19-22 janvier 2020

 

 

 

Modifié 3 février 2020 par chrismlt

[chrismlt]

Alert Notice 695: HST to observe V694 Mon (MWC 560)

 

February 3, 2020

  -   Campaigns and Observing Reports: https://www.aavso.org/v694-mon-campaign-2019
  -   Spectroscopy: https://www.aavso.org/v694-mon-campaign-2019-01

Further to AAVSO Alert Notice 692, Dr. Margarita Karovska (Center for Astrophysics|Harvard & Smithsonian) informs us that the symbiotic system V694 Mon (MWC 560) is currently scheduled to be observed with the Hubble Space Telescope on 2020 February 13 10-16 UT.

Dr. Karovska requests the following:

- nightly observations (UBVJHK (mid IR if possible) photometry and spectroscopy) beginning now.

- from February 11 through February 16, intense photometric monitoring in UBVJHK (mid IR if possible), including high speed photmetry if at all possible, and several spectra per night.

- beginning February 17 and continuing through the end of the observing season, photometry and spectroscopy at the cadence of two observations per week.

Recent observations of V694 Mon in the AAVSO International Database show the system at visual magnitude 8.8 on 2020 Feb. 3.08800 UT (M. Rana, Hampton, VA) and at 8.753 V +/-0.007 on 2020 Feb. 3.12145 UT (G. Stone, Auberry, CA). Its range is 8.64-12.2 V.

Spectroscopy observations should focus on the [OIII] 5007A line and the Halpha line regions. Spectroscopy reports (including plot, if possible) should be sent to Dr. Karovska (mkarovska@cfa.harvard.edu) and submitted to the AAVSO Spectroscopy Database (https://www.aavso.org/apps/avspec/).

Coordinates: R.A. 07 25 51.28   Dec. -07 44 08.2 (2000.0)

AAVSO finder charts for V694 Mon with comparison stars may be generated using the AAVSO Variable Star Plotter (VSP).

Please submit your optical observations to the AAVSO International Database using the name V694 MON.

This AAVSO Alert Notice was compiled by Elizabeth O. Waagen.

Modifié 3 février 2020 par chrismlt

[chrismlt]

AAVSO Alert Notice 696

R Aqr photometry (especially B) and spectroscopy needed February 3, 2020 AAVSO Forum threads (scroll to the bottom of a thread for latest posts): - Campaigns and Observation Reports: https://www.aavso.org/r-aqr-campaign-2019 - Long Period Variables: https://www.aavso.org/r-aqr-campaign-2019-01 - Spectroscopy: https://www.aavso.org/r-aqr-campaign-2019-02 The symbiotic binary (Mira + white dwarf) R Aqr has been the target of numerous observing campaigns and AAVSO Alert Notices, most recently AAVSO Alert Notices 689 and 665 . R Aqr is presently undergoing the eclipse that occurs about every 40 or so years. Photometry obtained to date shows extremely interesting short low amplitude variations with a timescale of 10 to 20 days, as well as what appear to be spikes. These variations are most significant in B. Researchers, including Dr. Margarita Karovska (Center for Astrophysics|Harvard & Smithsonian), Dr. Lee Anne Willson (Iowa State University), and Dr. George Wallerstein (University of Washington), are requesting continued close coverage of R Aqr in order to study these variations and other behaviors seen during this eclipse. Particularly crucial are B and V photometry - the B is critically important. Starting now, photometry is requested in UBVRIH (mid IR if possible). Nightly observations should be made. However, B (and V) observations should made twice per night, spaced 6-10 hours apart if possible so as to be most useful in studying the modulations seen in B. Nightly spectroscopic observations are also requested. Please continue these observations until further notice. Dr. Willson comments on the spikes seen in B that may be short-term outbursts. To help confirm if these spikes are real and, if so, to investigate their periodicity, she requests that anyone picking up a sudden rise in brightness follow it with time series. She adds that: "The reason why this is interesting is, in part, because we are probably looking at what is going on around the companion, and the time scales give us some limits on the sizes of the regions involved." R Aqr has a V range of 5.2 - 12.4. Current magnitudes from the AAVSO International Database are 12.4572 V +/- 0.0385 on 2020 Feb. 01.03461 UT (V. Buso, Rosario, Argentina) and 12.9897 B +/- 0.0364 on Feb. 01.03362 UT (Buso). Coordinates (J2000): R.A. 23 43 49.46  Dec. -15 17 04.2 Charts with comparison stars for R Aqr may be created using the AAVSO Variable Star Plotter (VSP). Please report all photometry observations to the AAVSO International Database using the name R AQR. Spectroscopy reports should be submitted to the AAVSO Spectroscopy Database (https://www.aavso.org/apps/avspec/) and to Dr. Karovska (mkarovska@cfa.harvard.edu). This Alert Notice was compiled by Elizabeth O. Waagen.

[jld37]

Très intéressant ces alertes, même si  les contraintes d'observation sont très élevées ....

A suivre avec plaisir...😀

JL

[chrismlt]

Ok, JLD. Merci pour ton retour.

Je me demandais si ça allait intéresser, ou pas. On est déjà pas très nombreux à cocher la case "photométrie" sur le CV, et du coup, je me suis dit que tout le monde recevait déjà les alertes, si ça se trouve ...

 

J'ai oublié de préciser, dans mon post initial, que ces alertes étaient également disponibles sur le site de l'AAVSO, bien entendu, et qu'on pouvait aussi les recevoir directement par mail, après inscription.

 

**

Ici, on est sur un mode de fonctionnement scientifique, alors c'est certain qu'il y a des contraintes, mais rien d'insurmontable. Pas plus que lorsqu'on fait une manip sur une exoplanète à confirmer, sous la houlette d'un professionnel, ou sur une occultation astéroidale.

Il faut voir que les professionnels sont toujours heureux de recevoir des observations de leur astre chouchou, du moment que c'est fait sérieusement, et avec de la bonne volonté, et c'est alors que le travail des amateurs prend tout son sens.

 

On peut généralement, et par ailleurs, discuter avec le professionnel qui lance l'alerte, soit directement sur un forum dédié via le site de l'AAVSO, ou en mail perso, une fois le contact établi. On discute alors méthodologie, éphémérides, et on peut avoir des news sur le phénomène en cours, son début, son évolution etc, par le truchement d'autres observateurs situés un peu partout dans le monde, qui observent la même chose, avec décalage temporel. Bien souvent, aussi, on a accès aux mesures du professionnel.

 

Pour avoir déjà participé à de telles manips, tout cela est très sympa et gratifiant, je trouve. Et il y a souvent un réel suspense ... Arrivera, arrivera pas, l'éclipse attendue depuis 3 ans ? Quelle sera la forme de la courbe, la profondeur ...

 

😉

 

 

 

Modifié 5 février 2020 par chrismlt

[jld37]

Je vais effectivement regarder de plus près les contraintes et attendre des ciels propices....😀

JL

[chrismlt]

Et une nouvelle NOVA, une !

 

***

 

AAVSO Alert Notice 697

Nova in Sagittarius: V6566 Sgr = N Sgr 2020 = PNV J17561375-2942546 February 4, 2020 AAVSO Forum threads (scroll to the bottom of a thread for latest posts):  - Time Sensitive Alerts: https://www.aavso.org/pnv-j17561375-2942546-possible-nova-115-mag-sagittarius  - Novae: https://www.aavso.org/v6566-sgr-n-sgr-2020-pnv-j17561375-2942546 Event: Nova in Sagittarius: V6566 Sgr = N Sgr 2020 = PNV J17561375-2942546 Discovered independently by: - Minoru Yamamoto (Okazaki, Aichi, Japan) (reported to CBAT by I. Endoh (NAO Japan)) - Yukio Sakurai (Mito, Ibaraki-ken, Japan) (reported to CBAT by S. Nakano (Sumoto, Japan)) Discovery magnitude:   - Yamamoto: unfiltered CCD mag 11.5 (using a Canon 6D DSLR camera with a 180-mm f/3.5 lens) - Sakurai: unfiltered CCD mag 10.5 (using a Nikon D7100 camera with a 180-mm f/2.8 lens)   Discovery date: - Yamamoto: 2020 January 30.8568 UT - Sakurai: 2020 January 31.841 UT Coordinates (2000.0): R.A. 17 56 14.04   Decl. -29 42 58.2  (from VSX) Spectra: Spectroscopy obtained by H. Akazawa (Funao, Kurashiki, Okayama, Japan) on 2020 Feb. 1.888 UT using a 0.35-m telescope (+ DSS-7 spectrograph + ST-402 camera) shows prominent H-alpha emission, characteristic of a nova. Observing recommendations: Observations of all types (visual, CCD, DSLR, spectroscopy) and multiple bands as instrumentation permits are strongly encouraged as the nova evolves. Observations reported to the AAVSO: 2020 Jan. 30.8568 UT, 11.5 CCD (M. Yamamoto, discovery image, via CBET 4720); 31.839, 11.5 CCD (Yamamoto, confirming image, via CBET 4720);   31.841, 10.5 CCD (Y. Sakurai, discovery image, via CBET 4720); Feb. 01.39604, 11.182 V +/-0.013 (J. Hambsch, Mol, Belgium); 01.39631, 11.187 V +/-0.014 (Hambsch); 01.39658, 9.303 I +/-0.031 (Hambsch); 01.39680, 9.344 I +/-0.031 (Hambsch); 01.39719, 12.451 B +/-0.028 (Hambsch); 01.39758, 12.385 B +/-0.029 (Hambsch); 01.752, 12.20 B (S. Kiyota, Kamagaya, Japan, iTelescope 0.50-m f/4.5 astrograph, Siding Spring, NSW, via CBET 4720); 01.752, 11.03 V (Kiyota); 01.752, 10.11 Rc (Kiyota); 01.752, 9.30 Ic (Kiyota); 01.83540, 11.6 (A. Pearce, Nedlands, WA, Australia); 01.876, 10.5 (K. Itagaki, Yamagata, Japan, via CBET 4720); 02.32569, <11.1 (C. Adib, Porto Alegre, Brazil); 02.39672, 11.673 V +/-0.016 (Hambsch); 02.39699, 11.666 V +/-0.017 (Hambsch); 02.39727, 9.662 I +/-0.033 (Hambsch); 02.39748, 9.685 I +/-0.035 (Hambsch); 02.39787, 12.926 B +/-0.039 (Hambsch); 02.39826, 12.855 B +/-0.041 (Hambsch); 02.83470, 11.7 (Pearce); 03.39734, 11.578 V +/-0.015 (Hambsch); 03.39762, 11.575 V +/-0.015 (Hambsch); 03.39790, 9.696 I +/-0.031 (Hambsch); 03.39811, 9.750 I +/-0.029 (Hambsch); 03.39851, 12.853 B +/-0.035 (Hambsch); 03.39889, 12.773 B +/-0.036 (Hambsch); 04.39804, 11.387 V +/-0.014 (Hambsch); 04.39831, 11.416 V +/-0.014 (Hambsch); 04.39859, 9.557 I +/-0.035 (Hambsch); 04.39880, 9.496 I +/-0.040 (Hambsch); 04.39920, 12.648 B +/-0.032 (Hambsch); 04.39958, 12.611 B +/-0.032 (Hambsch); Charts: A sequence for V6566 Sgr is being prepared by the AAVSO Sequence Team. Once it is available, charts with comparison stars for the nova may be created using the AAVSO Variable Star Plotter (VSP). Submit observations: Please submit observations to the AAVSO International Database using the name V6566 SGR. Notes: a. Designated PNV J17561375-2942546 when posted to the IAU Central Bureau for Astronomical Telegrams Transient Object Confirmation Page (TOCP). Information in this Alert Notice is taken from IAU CBAT CBET 4720 (D. W. E. Green, ed.) except for observations not indicated as coming via CBET 4720. b. E. Kazarovets reports that a red star (magnitudes B = 18.6, R = 16.6) is located at position end figures 13.781s, 57.68" (USNO-A2.0 0600-29573251). c. E. Kazarovets reports the GCVS name V6566 Sgr has been assigned to N Sgr 2020. d. Position end figures - H. Kaneda (measured Yamamoto's image of 2020 January 30.8568 UT): 13.75s, 54.6" - Sakurai (2020 Jan. 31.841 UT): 14.11s, 54.9" - S. Kiyota (2020 Feb. 01.752 UT): 14.04s, 58.0" - K. Itagaki (2020 Feb. 01.876 UT): 14.06s, 58.6" e. Images - S. Kiyota (2020 Feb. 01.752 UT): http://meineko.sakura.ne.jp/ccd/PNV_J17561375-2942546.jpg) - K. Itagaki (2020 Feb. 01.876 UT): http://k-itagaki.jp/images/sgr-2020-1.jpg) Congratulations to Minoru Yamamoto and Yukio Sakurai on their independent discoveries! This Alert Notice was compiled by Elizabeth O. Waagen.

[chrismlt]

Salut tous,   Difficile en première apparence à mag 18 et des puces, au pire, en seconde partie de nuit, les exigences ne sont pas très élevées, dans la mesure où, même une observation négative avec une mag "supérieure à", peut-être envoyée. Sous un bon ciel, mag 18 se fait en quelques minutes à la L100 + APN.   Bon ciel, C         AAVSO Alert Notice 698

V386 Ser to be observed with HST February 7, 2020 AAVSO Forum threads (scroll to the bottom of a thread for latest posts): - Campaigns and Observation Reports: https://www.aavso.org/v386-ser-campaign-2020 - Cataclysmic Variables: https://www.aavso.org/v386-ser-campaign-2020-01 Dr. Paula Szkody (University of Washington) has requested AAVSO assistance in monitoring the cataclysmic variable V386 Ser in support of observations scheduled with the Hubble Space Telecope for the week of 2020 February 17-28 UT to obtain a temperature and look for pulsation modes. Nightly snapshots are requested beginning now and continuing through February 29. Intensive monitoring is requested February 14-29; this period of intensive monitoring will be adjusted when the exact time of the HST observations is known. When the exact time is known, it will be posted to the AAVSO forum thread on this campaign (see above) and this Alert Notice will be updated online. During the period of intensive observations, prompt submission of observations will be critical. AAVSO observations are essential to know the state of the V386 Ser system in order to ensure that the system is NOT in outburst when observed with HST. AAVSO observations made 24 hours before the HST observing time will be used to make a go/no-go decision; AAVSO data will be used in the analysis of the resulting HST data. V386 Ser (UGWZ+ZZ/GWLIB = WZ Sge type with a non-radially pulsating white dwarf) is faint at quiescence (V~19.2). It had an outburst in January 2019, and on 2020 Feb 6.2159 UT it was V=18.409 +-0.161 (S. Dufoer, Brussels, Belgium). There is a V=17.757 star to the NW of the variable (178 in the AAVSO comparison star sequence; R.A. 16 10 33.15 Dec. -01 02 14.2); knowing whether the variable is fainter than, comparable to, or brighter than it will be very useful. If visual observers are unable to detect V836 Ser, please report any "fainter-than" estimates using the magnitude of the faintest comparison star magnitude seen. CCD observers are asked to use filters during observations if available; V is preferred. Detection of the variable itself is not required unless you can reach V=18.4 in reasonable time, but please use sufficient exposure to detect at least the 178 comparison star with a S/N of 10 and report the observation as a "fainter-than" observation. V386 Ser may be as bright as V=10.4 in outburst. Coordinates (J2000): R.A. 16 10 33.63  Dec. -01 02 23.2 Charts with a comparison stars for V386 Ser may be created using the AAVSO Variable Star Plotter (VSP). Please report all observations to the AAVSO International Database using the name V386 SER. V386 Ser has been the subject of previous AAVSO observing campaigns, with the most recent campaign having been covered in AAVSO Alert Notices 667, 669, and 675. This Alert Notice was compiled by Elizabeth O. Waagen.

[jld37]

Manque que le ciel......pour au  moins essayer....