Home

Optical Blazars, Quasar time delays AGNs Monitoring of blazars Force of Coriolis Astronomical Observatory Gallery of images 1 Gallery of images 2 Gallery of images 3 Gallery of images 4 Photos of sun pillars Addresses of interest

Discovery of AO Tau Discovery of AF Cam


adolfodarriba@
observatoriolascasqueras.es




Castellano Ingles
Study on the behavior of Blazars and Quasar

  • INTRODUCTION

  • In order to understand the Blazars, we must first recognize their behavior and this is where I focus my research on these highly variable brightness objects. In this study I consider to Blazars both objects BL LAC as Quasar OVV type, equal to simplify, which are a subtype of active galactic nuclei (AGNs).

    In both cases, they correspond to giant elliptical galaxies with relativistic jet directed toward us. If it were not this jet pointing towards us, it would be a quasar Seyfert type. Hence, there is a greater likelihood that the jet is not directed toward us and that is the main reason that fewer Blazars that quasar. Simply by simple probability.

    What I have clear is still being giant elliptical galaxies at cosmological distances being alone and only see the jet pointing towards us as a single point of light. That is, with optical telescopes see only a point without extension, so that all the observed variability occurs within the jet tube. The possible variability of the galaxy as a whole, would be unobservable.

    A fully observational fact is that Blazars are much more variable than Quasar and even very short scales objects. The Blazars simply because we are seeing the jet coming out of a very small region, practically the same accretion disk of a black hole. By contrast, the variability of normal Quasar is that the variation in brightness almost everything corresponds the galactic core, this being much larger region and can not change its faster brightness that it takes light to travel throughout this region, by the fact that the joint light would be attenuated by local variations.

    Theorizing a little, when an explosion occurs near the accretion disk of the black hole in the center of Blazar, detecting its counterpart with an explosion Gamma, the intense gravitational field rotation of the black hole, causing the displacement of space-time almost the speed of light, so that the magnetic lines are required to rotate on itself so quickly that the only way he has to leave the matter and highly ionized energy is its absolutely collimated magnetic poles through the two opposites, and on their way to the outside jet would helically.

    A special feature of Blazars is its synchrotron radiation and no thermal radiation which is normal in almost all objects in the universe, caused because matter and energy highly ionized moves through the lines of force, with the result the emission of synchrotron radiation. It does not occur because matter and energy are traveling at nearly the speed of light, in fact, so it is within the jet tube, but because it is continuously deflected by the magnetic field, emitting synchrotron radiation.

    For a greater understanding of these cosmological objects, attached some images from NASA.











  • OBSERVATIONAL ASTRONOMY
    • Period variability of each Blazar

  • And now deepening the compression of the Blazares strictly observational, it can be seen in the following light curves of the AAVSO database, that the Blazars are very random if we observe their light curves in years.

    Their amplitudes in luminosity are between 2.00 to 4.00 magnitudes in general. In Seyfert galaxies they usually have smaller amplitudes.

    Although Blazars are highly variable objects at very short scales in all their wavelengths (faster in Gamma rays or X-rays than in other wavelengths), the explosions produce a much faster increase of luminosity than normal , Staying a few days in the maximum and then descending almost as fast as it went up.

    Attached the following examples:

  • PKS 0716+71
  • (Per 1,000 days it produced approximately 7 luminosity increases, which corresponds on average to a period of about 145 days)

  • BL LAC
  • (Per 1,000 days it produced approximately 2.75 luminosity increases, which corresponds on average to a period of about 365 days)

  • 3C 66A
  • (Per 1,000 days it produced approximately 4 luminosity increases, which corresponds on average to a period of about 250 days)

  • MARK 421
  • (Per 1,000 days it produced approximately 5 luminosity increases, which corresponds on average to a period of about 200 days)



    BLAZAR
    PKS 0716+71
    (07 21 53.448 +71 20 36.36) z=0.300








    BLAZAR
    BL LAC
    (22 02 43.291 +42 16 39.98) z=0.069








    BLAZAR
    3C 66A
    (02 22 39.612 +43 02 07.88) z=0.34








    BLAZAR
    MARK 421
    (11 04 27.31394 +38 12 31.7991) z=0.031









    • Period between the primary and secondary explosion

  • A period of the variability of each Blazar, also occurs in a lot of them, a secondary explosion few days after the main outburst. In fact, this part of the curve is much more homogeneous than the rest of the path. This curve reminds us of the light curves of Type II-P supernovae (Plateau) as hump or mound. And even to Type Ia supernovae in the infrared.

    The explanation for this peculiar light curve of Type II-P supernovae is that they have a large hydrogen envelope that traps energy released as gamma rays and release it at lower frequencies. As seen in some blazars, at full brightness Gamma explosion occurs, so have many similarities to this type of supernovae. In addition, the section of the Plateau usually 100 days caused by the disintegration of Nickel 56 Cobalt 56, acting as a natural clock.

    A characteristic of the Blazars, which is common to all of them, is that after an explosion in the optical with its counterpart in Gamma rays, at that very moment a cascade of stable elements such as radioactive are the absolute responsible for the later behavior of the AGN represented in its light curve. Simply the secondary explosions are caused by the radioactive decay of some unstable element.

    As Blazars have an intense gravitational field would be expected to slow down over time, causing radioactive atoms disintegrate in times above normal. That yes, their percentage arrangement on development in the light curve would be equal to all of them, but only spaced in time, for time dilation, but this aspect of Blazars not appreciated.

    Most likely, the speed of rotation of the black hole in the core of Blazar along with intense magnetic force, determine the exact distance to the region of collimation of Blazar.

    As shown in the following examples, after a main explosion (marked in red 0 days) with its Gamma ray counterpart, (marked in blue) the curve is asymmetric. Only in Type III AGNs, as I define it, at 85 days there is an increase in brightness almost as bright as in the main explosion, but in this second explosion the curve is symmetrical at 88 days, quite the opposite Of the main explosion. In fact, only AGNs with true major explosions are Type III.

    With regard to Type I and Type II, intermediate scales may be produced, depending on how luminous the explosions are at 75 and 90 days. Those of Type I, after 60 days their light curve is flat and Type II, are prominent peaks. Such explosions are the most common. These are those AGNs that produce an increase in brightness of importance, without being defined as an exceptional explosion like Type III.

    All AGNs, both Blazars, Quasars, Seyfert galaxies 2, etc. Behave the same when an explosion occurs. The only difference is that the Seyfert galaxies 2 have smaller amplitudes as it happens.

    By comparing optical light curves with Gamma rays, Gamma rays have their maximum brightness from 1 to 4 days before the optics.

    As will be seen in the following light curves, each secondary explosion corresponds to the half-life of the radioactive isotopes generated exactly at the time of the main explosion.

    Of course, after 110 days, the light curve is totally random for most of the radioactive elements.

    Note: The blue crosses correspond to my observations. Thick crosses are made visually and fine crosses with CCD.

    As you can see in the following light curves of the AAVSO, there are three types of Explosions in the Blazars, which I have defined them as:










    Outburst Type I
    BLAZAR
    BL LAC
    (22 02 43.291 +42 16 39.98) z=0.069









    BLAZAR
    4C 11.69
    (22 32 36.40860 +11 43 50.8910) z=1.037
    The Astronomer’s Telegram. Nº 4409 Burst Gamma ray. 21 Sep 2012







    BLAZAR
    3C 454.3
    (22 53 57.748 +16 08 53.56) z=0.859
    The Astronomer’s Telegram. Nº 9157 Burst Gamma ray. 15 Jun 2016
    The Astronomer’s Telegram . Nº 1160 Burst Gamma ray. 27 Jul 2007










    QUASAR
    3C 279
    (12 56 11.16657 -05 47 21.5247) z=0.53620
    The Astronomer’s Telegram. Nº 10.188 Burst Gamma ray. 20 Mar 2017




    Light curve. NASA's Fermi Gamma-ray Space Telescope





    Types of radioactive disintegration
    Type I
    Outbursts secondary
    (Around 8 days)
    Iodine 131 to Xenon 131 --> Half life 8,02 days
    Selenium 72 to Astatine 72 --> Half life 8,40 days
    Thulium 167 to Erbium 167 --> Half life 9,25 days
    Erbium 169 to Thulium 169 --> Half life 9,40 days
    Actinium 225 to Fran­cium 221 --> Half life 10,00 days
    Iridium 193 to Iridium 193 --> Half life 10,5 days
    Barium 140 to Lanthanum 140 --> Half life 12,8 days

    (Around 18 days)
    Provoked as in the SN IIb
    Protactinium 230 to Thorium 230 --> Half life 17,40 days
    Arsenic 74 to Germanium 74 --> Half life 17,78 days
    Californium 253 to Einsteinium 253 --> Half life 17,81 days
    Californium 253 to Curium 249 --> Half life 17,81 days

    (Around 20 days)
    Einsteinium 253 to Berkelium 249 --> Half life 20,47 days

    (Around 30 days)
    Chromium 51 to Vanadium 51 --> Half life 27,70 days
    Protactinium 233 to Uranium 233 --> Half life 29,97 days
    Osmium 193 to Iridium 193 --> Half life 30,11 days
    Mendelevium 260 to Fermium 260 --> Half life 31,80 days
    Ytterbium 169 to Thulium 169 --> Half life 32,026 days
    Cerium 141 to Praseodymium 141 --> Half life 32,501 days
    Argon 37 to Chlorine 37 --> Half life 35,04 days

    (Around 50 days)
    Strontium 89 --> Half life 51,50 days
    Mendelevium 258 to Fermium 258 --> Half life 51,50 days
    Beryllium 7 to Lithium 7 --> Half life 53,12 days

    (Around 64 days)
    Zirconium 95 --> Half life 64,02 days




    Minimum in the light curves
    1º Minimum --> 60 days (First minimum important)

    2º Minimum --> 103 days (End of Plateau phase)








    Outburst Type II
    BLAZAR
    S5 0716+71
    (07 21 53.448 +71 20 36.36) z=0.300
    The Astronomer’s Telegram. Nº 6999 Burst Gamma ray. 27 Jan 2015
    The Astronomer’s Telegram . Nº 4447 Burst Gamma ray. 2 Oct 2012












    BLAZAR
    OJ 287
    (08 54 48.87493 +20 06 30.6410) z=0.306
    The Astronomer’s Telegram. Nº 8382 Burst Gamma ray. 8 Dec 2015
    The Astronomer’s Telegram . Nº 8777 Burst Gamma ray. 5 Mar 2016
















    QUASAR
    3C 279
    (12 56 11.16657 -05 47 21.5247) z=0.536










    BLAZAR
    3C 66A
    (02 22 39.612 +43 02 07.88) z=0.340
    The Astronomer’s Telegram . Nº 1753 Burst Gamma ray. 1 Oct 2008












    BLAZAR
    PKS 0735+178
    (07 38 07.394 +17 42 19.00) z=0.424








    BLAZAR
    S5 2007+77
    (20 05 31.004 +77 52 43.27) z=0.342
    The Astronomer’s Telegram. Nº 8635 Burst Gamma ray. 4 Feb 2016








    BLAZAR
    S4 0954+65
    (09 58 47.24510 +65 33 54.8181) z=0.367
    The Astronomer’s Telegram . Nº 8445 NIR Flare. 21 Dec 2015









    BLAZAR
    PKS 0048-09
    (00 50 41.31734 -09 29 05.2098) z=1.533







    BLAZAR
    S2 0109+224
    (01 12 05.82470 +22 44 38.7868) z=0.265
    The Astronomer’s Telegram . Nº 7844 Burst Gamma ray. 26 Jul 2015







    QUASAR
    PKS 0507+179
    (05 10 02.36913 +18 00 41.5817) z=0.416







    BLAZAR
    W COM
    (12 21 31.69052 +28 13 58.5002) z=0.10289




    Light curve. NASA's Fermi Gamma-ray Space Telescope




    Types of radioactive disintegration
    Type II
    Outbursts secondary
    (Around 8 days)
    Iodine 131 to Xenon 131 --> Half life 8,02 days
    Selenium 72 to Astatine 72 --> Half life 8,40 days
    Thulium 167 to Erbium 167 --> Half life 9,25 days
    Erbium 169 to Thulium 169 --> Half life 9,40 days
    Actinium 225 to Fran­cium 221 --> Half life 10,00 days
    Iridium 193 to Iridium 193 --> Half life 10,5 days
    Barium 140 to Lanthanum 140 --> Half life 12,8 days

    (Around 18 days)
    Provoked as in the SN IIb
    Protactinium 230 to Thorium 230 --> Half life 17,40 days
    Arsenic 74 to Germanium 74 --> Half life 17,78 days
    Californium 253 to Einsteinium 253 --> Half life 17,81 days
    Californium 253 to Curium 249 --> Half life 17,81 days

    (Around 20 days)
    Einsteinium 253 to Berkelium 249 --> Half life 20,47 days

    (Around 30 days)
    Chromium 51 to Vanadium 51 --> Half life 27,70 days
    Protactinium 233 to Uranium 233 --> Half life 29,97 days
    Osmium 193 to Iridium 193 --> Half life 30,11 days
    Mendelevium 260 to Fermium 260 --> Half life 31,80 days
    Ytterbium 169 to Thulium 169 --> Half life 32,026 days
    Cerium 141 to Praseodymium 141 --> Half life 32,501 days
    Argon 37 to Chlorine 37 --> Half life 35,04 days

    (Around 50 days)
    Strontium 89 --> Half life 51,50 days
    Mendelevium 258 to Fermium 258 --> Half life 51,50 days
    Beryllium 7 to Lithium 7 --> Half life 53,12 days

    (Around 64 days)
    Zirconium 95 --> Half life 64,02 days

    (Around 70 days)
    Cobalt 58 to Iron 58 --> Half life 70,86 days
    Iridium 192 to Platinum 192. Half life 73,827 days
    Iridium 192 to Osmium 192. Half life 73,827 days
    Tungsten 185 to Rhenium 185. Half life 75,10 days
    Cobalt 56 to Iron 56 --> Half life 77,27 days

    (Around 90 days)
    Tecnecio 97 to Molibdeno 97 --> Half life 90 days
    Thulium 168 to Erbium 168 --> Half life 93,10 days
    Osmium 185 to Rhenium 185 --> Half life 93,60 days




    Minimum in the light curves
    1º Minimum --> 60 days (First minimum important)

    2º Minimum --> 103 days (End of Plateau phase)








    Outburst Type III





    BLAZAR
    S5 1803+78
    (18 00 45.684 +78 28 04.02) z=0.680
    The Astronomer’s Telegram. Nº 7933 Burst Gamma ray. 20 Aug 2015




    Light curve. NASA's Fermi Gamma-ray Space Telescope




    BLAZAR
    OJ 287
    (08 54 48.87493 +20 06 30.6410) z=0.306
    The Astronomer’s Telegram. Nº 9489 Burst Gamma ray. 13 Sep 2016




    Light curve. NASA's Fermi Gamma-ray Space Telescope




    QUASAR
    4C 11.69 = CTA 102
    (22 32 36.4 +11 43 51) z=1.037




    Light curve. NASA's Fermi Gamma-ray Space Telescope




    QUASAR
    S5 1044+71
    (10 48 27.6 +71 43 36) z=1.150




    Light curve. NASA's Fermi Gamma-ray Space Telescope




    BLAZAR
    OT 081
    (17 51 32.81855 +09 39 00.7288) z=0.322
    The Astronomer’s Telegram. Nº 9231 Burst Gamma ray. 11 Jul 2016








    QUASAR
    S4 1800+44
    (18 01 32.31481 +44 04 21.9004) z=0.663
    The Astronomer’s Telegram. Nº 8812 Burst Gamma ray. 14 Mar 2016








    SEYFERT 1 GALAXY
    S4 1030+61
    (10 33 51.42726 +60 51 07.3301) z=1.400
    The Astronomer’s Telegram. Nº 9009 Burst Gamma ray. 29 April 2016




    Light curve. NASA's Fermi Gamma-ray Space Telescope




    BLAZAR
    PKS 0048-09
    (00 50 41.31734 -09 29 05.2098) z=0.635







    Types of radioactive disintegration
    Type III
    Outbursts secondary
    (Around 8 days)
    Iodine 131 to Xenon 131 --> Half life 8,02 days
    Selenium 72 to Astatine 72 --> Half life 8,40 days
    Thulium 167 to Erbium 167 --> Half life 9,25 days
    Erbium 169 to Thulium 169 --> Half life 9,40 days
    Actinium 225 to Fran­cium 221 --> Half life 10,00 days
    Iridium 193 to Iridium 193 --> Half life 10,5 days
    Barium 140 to Lanthanum 140 --> Half life 12,8 days

    (Around 18 days)
    Provoked as in the SN IIb
    Protactinium 230 to Thorium 230 --> Half life 17,40 days
    Arsenic 74 to Germanium 74 --> Half life 17,78 days
    Californium 253 to Einsteinium 253 --> Half life 17,81 days
    Californium 253 to Curium 249 --> Half life 17,81 days

    (Around 20 days)
    Einsteinium 253 to Berkelium 249 --> Half life 20,47 days

    (Around 30 days)
    Chromium 51 to Vanadium 51 --> Half life 27,70 days
    Protactinium 233 to Uranium 233 --> Half life 29,97 days
    Osmium 193 to Iridium 193 --> Half life 30,11 days
    Mendelevium 260 to Fermium 260 --> Half life 31,80 days
    Ytterbium 169 to Thulium 169 --> Half life 32,026 days
    Cerium 141 to Praseodymium 141 --> Half life 32,501 days
    Argon 37 to Chlorine 37 --> Half life 35,04 days

    (Around 50 days)
    Strontium 89 --> Half life 51,50 days
    Mendelevium 258 to Fermium 258 --> Half life 51,50 days
    Beryllium 7 to Lithium 7 --> Half life 53,12 days

    (Around 64 days)
    Zirconium 95 --> Half life 64,02 days

    (Around 85 days)
    Nickel 56 to Iron 56 --> 83,35 days
    (Nickel 56 to Cobalt 56 --> Vida media 6,08 days) +
    (Cobalt 56 to Iron 56 --> Half life 77,27 days) = 83,35 days
    Arsenic 73 to Germanium 73 --> Half life 80,30 days
    Zirconium 88 to Yttrium 88 --> Half life 83,40 days
    Scandium 46 to Titanium 46 --> Half life 83,79 days

    (Around 87 days)
    Sulfur 35 to Chlorine 35 --> Half life 87,32 days

    (Around 93 days)
    Thulium 168 to Erbium 168 --> Half life 93,10 days
    Osmium 185 to Rhenium 185 --> Half life 93,60 days

    (Around 120 days)
    Selenium 75 to Astatine 75 --> Half life 119,779 days
    Tungsten 181 to Tantalum 181 --> Half life 121,2 days

    (Around 128 days)
    Thulium 170 to Ytterbium 170 --> Half life 128,6 days

    (Around 138 days)
    Polonium 210 to Lead 206 --> Half life 138,376 days

    (Around 207 days)
    Rhodium 102 to Ruthenium 102 --> Half life 207,0 days

    (Around 272 days)
    Cobalt 57 to Iron 57 --> Half life 271,79 days

    (Around 285 days)
    Cerium 144 to Praseodymium 144 --> Half life 284,893 days

    (Around 374 days)
    Ruthenium 106 to Rhodium 106 --> Half life 373,59 days

    (Around 462 days)
    Cadmium 109 to Silver 109 --> Half life 462,6 days

    (Around 754 days)
    Caesium 134 to Xenon 134 --> Half life 754,17 days
    Caesium 134 to Barium 134 --> Half life 754,17 days

    (Around 960 days)
    Promethium 147 to Samarium 147 --> Half life 958,20 days




    Minimum in the light curves
    1º Minimum --> 60 days (First minimum important)

    2º Minimum --> 103 days (End of Plateau phase)








    Blazar Intermedio

    Intermediate Blazar
    They are objects that have properties of Blazars as Seyfert galaxies type 1 as the Quasar, for its slow variation over time and with lower amplitudes. The light curve is much more defined.

    BLAZAR
    S4 1749+70
    (17 48 32.840 +70 05 50.77) z=0.770







    SEYFERT 1 GALAXY
    3C 390.3
    (18 42 08.9899 +79 46 17.128) z=0.056







    BLAZAR
    1ES 1959+65
    (19 59 59.8521 +65 08 54.653) z=0.047







    QUASAR
    QSO B1803+6737
    (18 03 28.9037 +67 38 10.529) z=0.135








    • Examples of Type Ia Supernovae

  • The following light curves correspond to Type Ia supernovae. As you can see below, the curves of light in the infrared (red), are quite similar to the curves in visual in Blazars.

    After the maximum brightness, it occurs last about 28 days, a secondary explosion. This increased brightness corresponds to the disintegration of a radioactive element.

    Even the amplitude of about 0.5 magnitudes is common to them all.



    SN 2014J - M82. Type Ia (09 55 42.12 +69 40 25.9)





    SN 2011BY - NGC 3972. Type Ia (11 55 45.56 +55 19 33.8)








    • Examples of Type II-P supernovae

  • The following light curve corresponds to Type II-P supernovae (Plateau). As you can see, for 85 days you have a soft fall. Reaching 100 days, the fall is much steeper. This occurs both visual and infrared.



    SN 2013EJ - M74. Type II-P (01 36 48.16 +15 45 31.0)






    • Examples of Type IIb supernovae

  • In the following example, it corresponds to the Supernova SN 1993J Type IIb. As can be seen, it occurs 18 days later the maximum brightness, a secondary explosion.

    As can be seen in this light curve, it has great similarities with Blazars with main and secondary explosion, although the physical processes are quite different.



    SN 1993J - M81. Type IIb (09 55 24.775 +69 01 13.70)








    • Conclusions

  • It is clear that more observations are needed to verify really if my theory is correct. So my intention is to observe all these objects to make a more accurate light curve and check any recognizable patterns.

    With these observations, it is not apparent that there is a direct correlation between the period of each Blazar and its distance. Also not would expect.

    But if those who have a small amplitude (about 2.00 magnitudes) have short periods (less than 100 days), and those who have large amplitudes, (about 4.00 magnitudes) have long periods (more than one year).

    As each Blazar always has the same massive core, the same speed of rotation of the black hole, the same gravitational and magnetic intensity, the region where all this activity Gamma is generated with its counterpart in the optical, it will be defined at a given distance from Blazar core. That is why some should be relantizados by time, and this is not observed in any of them.

    While Blazars at cosmological distances at high redshift, which in fact are alleged to us at nearly the speed of light, and added with a huge gravitational field, and that the region collimation must be really accretion disk near or on the periphery, it is not understood that the temporary slowdown of radioactive elements does not exist. At this point it is where most disconcerts me these objects.

    To try to solve the problem of nonexistent temporary slowdown, we should assume that the collimation region where all the activity occurs Blazar is really far from the black hole. Simply to solve the problem of the temporary slowdown caused by the immense gravitational field, but would also have the problem caused by the high redshift.

    It is clear that although the mechanism of ignition, temperature, speed of the shock wave and the subsequent expulsion of the gamma rays must have some resemblance to the Supernovas, like radioactive elements generated in such an explosion, explosions supernovae have an asymmetric evolution, opposite to that of blazars which is symmetrical through the collimating region.

    In fact, the light curves of different types of supernovae and significant increases in brightness, corresponds to the secondary explosions in Blazars. The first secondary explosion reminiscent of Type IIb supernovas, around 18 days and arrived at 100 days, falling brightness of the Plateau phase in Type II-P supernovae seen.

    In Supernovae, Gamma rays are detected much later than the main explosion, and even later to reach their maximum brightness since the outer layers of the exploding star are opaque. It is for that reason that after a time, the layers become transparent when the star is expanded and is when it could be detected. In the case of Blazars, the gamma burst is detected at maximum brightness and even a few days earlier because all the radiation leaves a very small collimation region and within the particle jet, there is practically radiation, not matter.

    All this speculation would be solved with a spectral analysis done in the main explosion, in the secondary explosions and in its minimum of brightness. Comparing the results, we would verify that chemical elements produce the brightness of Blazar








    • My more immediate objectives

  • Monitoring from the main explosion to the next 110 days which is when its brightness is absolutely random.

    Define the exact moment when the main and secondary explosions explosion occurs, to verify whether there is a time delay.

    Study Blazars just the tenth day after the main explosion, because an increase in glow that lasts only several hours a day is also produced and this is a challenge that I can follow.

    To verify that this pattern of behavior of the Blazares is extendible to all the AGNs, as it seems it. As is normal, Seyfert type II galaxies have smaller amplitudes.

    Monitor the various Blazars if an explosion occurs and thus inform the scientific community as to the AAVSO and the group of scientists from NASA's Fermi for further study at all wavelengths.



    • Gratefulness

  • I thank the AAVSO for permission to publish their light curves and the M1 Group for their important contribution. Also to all observers who have made these observations, without them, this work would not have been possible. To all of them, thank you very much.

    Also the NASA Fermi Group to authorize publish their light curves in gamma rays for a greater understanding of these objects.




    Home Ir arriba