The size, shape, density and ring of the dwarf planet Haumea from a stellar occultation
Haumea—one of the four known trans-Neptunian dwarf planets—is a very elongated and rapidly rotating body1, 2, 3. In contrast to other dwarf planets4, 5, 6, its size, shape, albedo and density are not well constrained. The Centaur Chariklo was the first body other than a giant planet known to have a ring system7, and the Centaur Chiron was later found to possess something similar to Chariklo’s rings8, 9. Here we report observations from multiple Earth-based observatories of Haumea passing in front of a distant star (a multi-chord stellar occultation). Secondary events observed around the main body of Haumea are consistent with the presence of a ring with an opacity of 0.5, width of 70 kilometres and radius of about 2,287 kilometres. The ring is coplanar with both Haumea’s equator and the orbit of its satellite Hi’iaka. The radius of the ring places it close to the 3:1 mean-motion resonance with Haumea’s spin period—that is, Haumea rotates three times on its axis in the time that a ring particle completes one revolution. The occultation by the main body provides an instantaneous elliptical projected shape with axes of about 1,704 kilometres and 1,138 kilometres. Combined with rotational light curves, the occultation constrains the three-dimensional orientation of Haumea and its triaxial shape, which is inconsistent with a homogeneous body in hydrostatic equilibrium. Haumea’s largest axis is at least 2,322 kilometres, larger than previously thought, implying an upper limit for its density of 1,885 kilograms per cubic metre and a geometric albedo of 0.51, both smaller than previous estimates1, 10, 11. In addition, this estimate of the density of Haumea is closer to that of Pluto than are previous estimates, in line with expectations. No global nitrogen- or methane-dominated atmosphere was detected.
Lajatico astronomical observatory pubblications.
Optical and X-ray behaviour of the high mass X-ray transient A0535+26/HDE245770 in February-March 2014
The optical behaviour of the Be star in the high-mass X-ray transient A0535+26/HDE245770 shows that at periastron the luminosity is typically enhanced by 0.02 to a few tenths magnitude, and the X-ray outburst occurs eight days after the periastron. Indeed, at the periastron an increase of the mass flux occurs. This sort of flush reaches the external part of the temporary accretion disk around the neutron star and moves to the hot central parts of the accretion disk and the neutron star surface. The time necessary for this way is dependent on the turbulent viscosity in the accretion disk, as discussed by Giovannelli, Bisnovatyi-Kogan, and Klepnev (2013) (GBK13). In this paper we will show the behaviour of this system in optical band around the predicted periastron passage on 21st February 2014, by using the GBK13 ephemeris that we used to schedule our spectroscopic and photometric optical observations. Spectroscopic unusual activity detected in the Balmer lines and the enhancement in the emission in B, V, and R bands around the periastron passage, and the subsequent X-ray event definitively demonstrate the existence of about 8 day delay between optical and X-ray flares.
Link to web site: http://arxiv.org/abs/1409.3434
Survey of Period Variations of Superhumps in SU UMa-Type Dwarf Novae. IV: The Fourth Year (2011-2012)
Pubblication of the transit HD 189733 b in collaboration with Czech Astronomical Society . Authors Fabio Martinelli and Giorgio Corfini.
Pubblication of the transit KOI0135 b in collaboration with Czech Astronomical Society . Authors Fabio Martinelli and Giorgio Corfini.
Pubblication of the transit HD 189733 b in collaboration with Czech Astronomical Society . Authors Fabio Martinelli and Giorgio Corfini.
Pubblication of the transit KOI 0196 b in collaboration with Czech Astronomical Society . Authors Fabio Martinelli and Giorgio Corfini.
Pubblication of the transit TRES-3 in collaboration with Czech Astronomical Society . Authors Fabio Martinelli and Giorgio Corfini.
Pubblication of obsevation of SN in NGC 5775 in collaboration with ISSP, Italian Supernovae Search Project, Observation by Fabio Martinelli and Fabio Briganti.
Pubblication of the transit Wasp-14 in collaboration with Czech Astronomical Society & Luigi Mancini Max Plank Instutute for astronomy Germany. Authors Fabio Martinelli and Giorgio Corfini.
Telescope Cassegrain 356 mm focal lenth 2500 CCD SBIG ST8XME KAF1600.
Pubblication of the transit GJ1214 in collaboration with Czech Astronomical Society & Luigi Mancini Max Plank Instutute for astronomy Germany. Authors Fabio Martinelli and Giorgio Corfini.
Telescope Cassegrain 302 mm focal lenth 2000 CCD SBIG KAF1600.
Exoplanet transit of WASP-43 By Fabio Martinelli and data reduction by Giorgio Corfini Telescope 356 mm focal lenth 2257 mm, CCD camera ST-8XME Baader yellow filter 495nm.
Latest supernovae, discovered SN in NGC 5806
Discovered a SN by Fabio Briganti and Alessandro Dimai in NGC 5806. The transient, discovered by Fabio Briganti (Santa Croce sull’Arno – PI) in poor seeing condition, with the SC 11″ f/6,3 of the Col Drusciè Observatory, in the cours of Italian Supernovae Search Project, needs a confirmation, because there is only a frame of the suspect. No known minor planets in the field at the time of discovery. Nothing is visible in red and blue plates of Palomar Sky Survey POSS2.
you can find the discovery image.
Congratulation to Fabio Briganti and Alessandro Dimai Up date about the SN in NGC 5806 cause it’s very interesting and bright supernova.
The PTF (ATEL #1964, #3253; http://www.astro.caltech.edu/ptf ) reports the discovery of a new supernova in NGC 5806 (independently discovered by F. Briganti and reported as PSN J14595904+0153251 on Jan 22). The source is located at RA = 14:59:59.08, Dec = +01:53:24.2 (J2000), was first detected by the Palomar 1.2m telescope with an R-band magnitude of about 17 on 2012 Jan 10 (UT) and brightened to about 16.1 mag on Jan 20. PTF did not detect the source prior to 2012 Jan 5. Spectroscopic follow-up was performed with the HET (+LRS) on Jan 14, the INT (+IDS) on Jan 15-18, Gemini N (+GMOS) on Jan 17 and the Palomar 5m (+DBSP) on Jan 18. The spectra show prominent H features as well as He absorption at about 10,000 km/s, consistent with a type IIb classification. Credential Certification: Christopher J. Stockdale (email@example.com)
Subjects: Radio, X-ray, Supernovae
We report the detection of radio emission near the position of the type-IIb supernova PTF2012os (ATEL #3881) with the Karl G. Jansky Very Large Array radio telescope in the DnC configuration: A flux density of 0.44 +/- 0.05 mJy was measured at 5.02 GHz (wavelength 6.0 cm) on 2012 Jan. 22.42 UT. The measured position of the radio emission of R.A. = 14h59m59.s12, Decl. = +01d53m23s.3, equinox 2000.0 is in good agreement with the measured optical position of (ending digits) R.A. = 59.s08, Decl. = 24s.2, equinox 2000.0 (ATEL #3881). Radio observations are continuing. Using 9.4 ks of co-added Swift X-Ray Telescope (XRT) data, obtained on 2012-01-14 (2.0 ks exposure time; PI Kasliwal), 2012-01-16 (2.4 ks; PI Kasliwal), and 2012-01-24 (5.0 ks; PI Immler), no X-ray source is detected at the position of the SN. The PSF, dead-time, and vignetting corrected upper limit to the XRT net count rate is 1.1E-03 cts/s (3-sigma), corresponding to an unabsorbed (0.2-10 keV band) X-ray flux limit of 5.4E-14 erg/cm/cm/s and a luminosity limit of 4.2E39 erg/s for an adopted thermal plasma spectrum with a temperature of kT = 10 keV, a Galactic foreground column density of 4.14E+20 (Dickey & Lockman, 1990, ARAA 28) and a distance of 25.4 Mpc (NED). Swift observations are continuing. The object warrants further study in all wavelength bands. Credential Certification: Schuyler D. Van Dyk (firstname.lastname@example.org)
Schuyler D. Van Dyk (Spitzer Science Center/Caltech), Avishay Gal-Yam, Iair Arcavi (Weizmann Institute), Mansi M. Kasliwal (OCIW/Princeton), and Assaf Horesh (Caltech), on behalf of the larger PTF collaboration, report their attempt to identify the progenitor of the Type IIb supernova PTF12os, aka PSN J14595904+0153251, in archival Hubble Space Telescope (HST) ACS/WFC F435W, F555W, and F814W images from 2005 March 10 UT (PI: Smartt). We have astrometrically matched a B-band image (with 0.87″ seeing) from 2012 January 18 UT obtained with the IMACS camera on the Magellan Baade 6.5 m telescope at Las Campanas Observatory, Chile, with the ACS F435W image, using 10 fiducial stars in common. The SN position has been located on the ACS image with an uncertainty of 0.57 WFC pixel, or 0.028″. This is within 1 WFC pixel, to the southwest, of a candidate source detected in all three ACS bands. The site of PTF12os lies approximately 2.2″ southeast of the position of the Type II SN 2004dg in this same host galaxy. Preliminary photometry of the ACS images using Dolphot (Dolphin 2000, PASP, 112, 1383) results in a brightness for the object of B=23.30, V=23.04, and I=22.53 (uncertainties are all 0.012 mag or smaller). Assuming the average value of the distance modulus to the host, NGC 5608, from the NASA/IPAC Extragalactic Database (NED), 32.01 mag, and also assuming only the Galactic foreground extinction at V-band from Schlegel, Finkbeiner, & Davis (1998, ApJ, 500, 525), 0.17 mag, this object had V absolute magnitude of -9.1 and absolute colors (B-V)_0=0.21 and (V-I)_0=0.44 (consistent with an early F spectral type). This could be a highly-luminous supergiant star, or, alternatively, a compact star cluster. Evidence exists from the strength of the Na I D lines in follow-up spectra (ATel 3881) that the extinction to the SN could, in fact, be higher, implying that the source is even more luminous and bluer. We tentatively identify this source as a candidate for the progenitor, although given the offset of the SN position from the object’s centroid, the host galaxy distance, and the inferred higher extinction, it is quite possible that the progenitor has not been detected. Higher-resolution imaging is pending for candidate confirmation, and further analysis is ongoing. Credential Certification: Assaf Horesh (email@example.com)
Subjects: Millimeter, Supernovae
We report a CARMA observation of the type IIb supernova PTF12os (Arcavi et al.; ATEL# 3881). The observation was undertaken on 2012 Jan 14.65 UT. We report a null-detection in the 3-mm band (at a center frequency of 93 GHz) with a 3 sigma upper limit of 0.36 mJy/beam. We thank the CARMA staff for scheduling this target of opportunity. Pubblicazione della scoperta.
Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION CBAT Director: Daniel W. E. Green; Hoffman Lab 209; Harvard University; 20 Oxford St.; Cambridge, MA 02138; U.S.A. e-mail: firstname.lastname@example.org (alternate email@example.com) URL http://www.cbat.eps.harvard.edu/index.html Prepared using the Tamkin Foundation Computer Network SUPERNOVA 2012P IN NGC 5806 = PSN J14595904+0153251 Alessandro Dimai, Cortina d'Ampezzo, Italy, on behalf of the Italian Supernovae Search Project (ISSP), reports the discovery by Fabio Briganti (Santa Croce sull'Arno, Pisa, Italy) of an apparent supernova (mag about 15.0) on unfiltered CCD images (limiting mag about 16.5) taken with the "Maioni" 0.28-m telescope of the Osservatorio Astronomico del Col Druscie at Cortina d'Ampezzo, Italy, on Jan. 22.1556 UT. The new object is located at R.A. = 14h59m59s.12, Decl. = +1d53'24".4 (equinox 2000.0), which is 10" west and 1" south of the nucleus of NGC 5806. Nothing is visible at this position on Palomar Sky Survey infrared, red, and blue plates. The discovery image is posted at website URL http://tinyurl.com/7lzoeyv. The variable was designated PSN J14595904+0153251 when it was posted at the Central Bureau's TOCP webpage and is here designated SN 2012P based on the spectroscopic confirmation reported below. Additional CCD magnitudes for 2012P (unfiltered unless noted otherwise): 2011 Dec. 7, [18.0 (ISSP); 2012 Jan. 23.227, 15.2 (Briganti); 23.549, 16.3 (Joseph Brimacombe, Cairns, Australia; remotely using a 51-cm RCOS telescope + STL11K camera + luminance filter at the New Mexico Skies Observatory near Mayhill, NM, U.S.A.; position end figures 59s.09, 24".1; image posted at URL http://www.flickr.com/photos/43846774@N02/6752536997/). The type-II supernova 2004dg also appeared in NGC 5806 (cf. IAUC 8375). L. Borsato and V. Nascimbeni, Dipartimento di Fisica e Astronomia, Universita di Padova; and S. Benetti, A. Pastorello, S. Valenti, L. Tomasella, E. Cappellaro, P. Ochner, and M. Turatto, Osservatorio Astronomico di Padova, Istituto Nazionale di Astrofisica, report that a spectrum (range 360-810 nm; resolution 2.2 nm) of PSN J14595904+0153251 = SN 2012P was obtained on Jan. 23.17 UT with the Ekar-Copernico 1.82-m telescope (+ AFOSC). Using a library of supernova spectra via GELATO (Harutyunyan et al. 2008, A.Ap. 488, 383; available via https://gelato.tng.iac.es/login.cgi), they found a best match with typical type-Ib/c supernovae soon after maximum if a redshift of z = 0.004533 (Falco et al. 1999, PASP 111, 438; via NED) is assumed. From the minimum of a deep-intense absorption measured at 627.6 nm, an expansion velocity of about 5100 km/s is deduced for the ejecta if identified with Si II 635.5-nm (but an expansion velocity of about 14400 km/s if identified with H-alpha). NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2012 CBAT 2012 January 25 (CBET 2993) Daniel W. E. Green
DISCOVERY SUPERNOVA IN NGC 7485
Just one mounth we started the astronomical search, and we have the first Supernova discovered by Montecatini val di Cecina astronomical association. During the night of 13th october 2011 the survery for Supernova search with C14 telescope, Bellincioni Beta mount using DTA camera with Kodak KAF1000, Fabio Martinelli get an image of galaxy NGC 7485. During the controll By Riccardo Mancini.
we discovered the SN of Magnitude 17.00.
The pubblication about PSN by IAU, International astronomical union. http://www.cbat.eps.harvard.edu/unconf/followups/J23060280+3406367.htmlA. Dimai, Cortina d’Ampezzo, Italy, reports the discovery by Fabio Martinelli, Riccardo Mancini and Fabio Briganti, on behalf of Italian Supernovae Search Project, of an apparent supernova (see PSN J23060280+3406367), on unfiltered CCD images taken with the 0.35-m telescope of the Montecatini Valdicecina Observatory (Pisa – Italy) on October 14.0299 (at mag about 18.0; limiting mag about 19.0) and 14.9319 UT (mag about 17.6; limiting mag about 19.0). The new object is located at R.A. = 23h06m02s.80, Decl. = +34°06’36”.7 (equinox 2000.0), which is 22″ west and 8″ north of the nucleus of NGC 7485. ISSP images of the same field taken on 2011 Oct. 01 (limiting mag about 19.5) shows nothing at this position, nor do Palomar Sky Survey infrared, red, and blue plates. A confirmation image, taken by A. Dimai with the „Maioni” 0.28 m. telescope of the Col Drusciè Observatory on October 15.9, shows the PSN at mag. +17.0 C. Best Regards Alessandro Dimai We are glad to get this discovered. Montecatini astronomical association.
J231935.0+364705: superhumps evolution
Denis Denisenko d.v.denisenko at gmail.com Fri Oct 7 17:55:49 JST 2011 Fabio Martinelli (Astronomical Centre at Montecatini, Italy) has obtained fifty 160-sec exposures of J2319+3647 covering 2.3 hours interval from 00:58 to 03:18 UT on 2011 Oct. 05. Light curve (unfiltered magnitudes with Red zero point) is uploaded to http://pics.livejournal.com/bigdenru/pic/000adk0k/ I was using R=14.4 as the comparison star and R=14.2 as check star from my 2007 finder chart at http://hea.iki.rssi.ru/~denis/J2319+3647-comps.gif Amplitude of orbital modualtion has decreased to 0.13-0.14m. It was 0.24m during Oct. 01/02 observations by Etienne Morelle. Denis Denisenko P.S. Regarding the new object from vsnet-alert 13736: dwarf nova 1RXS J231935.0+364705 is also a hard ROSAT source (HR1=1.00+/-0.09, HR2=0.47+/-0.16).
Observation of the last SN in M101 by our observatory show how is been fast the light curve of the Supernova in M101 Immage by latest supernovae .
Pubblication by Coelum magazine about Italian Supernovae Search Project. ISSP Magazine pubblication Italian language only.
Observations and Pubblication during telescopes test and previus the observatory opening.
Pre-discovery Immage of SN near NGC 6577 observed 27/06/2011. Immage by Fabio Martinelli, Survey controll by Fabio Briganti. Telescope SC 14″ immage with DTA camera KAF1000 60 sec exp, telescope test Montecatini VdC Astronomical Association SN Discoverde by Fabrizio Ciabattari, S. Donati e G. Fornaciari Italian Supernovae Search Project.
SN Immage observed 23/05/2011 in UGC10018 galaxy Telescope C14 celestron ccd camera DTA KAF1000 60 sec exp By Fabio Martinelli e Mauro Biagetti communicated to Latest Supernovae. Montecatini VdC Astronomical Association.