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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

5559 results found.

  1. Swift GRB200306.01: Global MASTER-Net observations report
  2. GRB 200228B: continued optical observations
  3. LIGO/Virgo S200302c: AstroSat CZTI upper limits
  4. GRB 200303A: Fermi GBM observation
  5. GRB200210A AstroSat observations
  6. LIGO/Virgo S200302c: Upper limits from Insight-HXMT/HE observations
  7. GRB 200303A: NOT optical observations
  8. GRB 200303A: GOTO observations upper limit
  9. GRB 200303A: Optical limit from CAHA
  10. LIGO/Virgo S200302c: No transient candidates in CALET observations
  11. Swift GRB200303.11: Global MASTER-Net observations report
  12. Fermi trigger No 604895668: Global MASTER-Net observations report
  13. LIGO/Virgo S200224ca: No counterpart candidates in TOROS observations
  14. LIGO/Virgo S200302c: No significant counterpart candidates in Fermi-LAT observations
  15. LIGO/Virgo S200302c: No counterpart candidates in KAIT observations
  16. LIGO/Virgo S200302c: no counterpart candidates in the Swift/BAT observations
  17. LIGO/Virgo S200302c: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  18. LIGO/Virgo S200302c : no neutrino counterpart candidate in ANTARES search
  19. LIGO/Virgo S200302c: upper limits from AGILE/MCAL observations
  20. LIGO/Virgo S200219ac: AstroSat CZTI upper limits
  21. LIGO/Virgo S200302c: Coverage and upper limits from MAXI/GSC observations
  22. LIGO/Virgo S200302c: Upper limits from IceCube neutrino searches
  23. LIGO/Virgo S200302c: Identification of a GW compact binary merger candidate
  24. LIGO/Virgo S200302c: Global MASTER-Net observations report
  25. GRB 200228B: Mondy, TSHAO, AbAO and CrAO optical observations, afterglow candidate
  26. LIGO/Virgo S200225q : No significant candidates in TAROT - FRAM - GRANDMA observations.
  27. LIGO/Virgo S200213t: No significant EM counterparts identified from continued GECKO observation of host galaxy candidates
  28. LIGO/Virgo S200224ca : No significant candidates in TAROT - FRAM - GRANDMA observations
  29. LIGO/Virgo S200224car: GRAWITA VST-ESO PARANAL observations.
  30. LIGO/Virgo S200225q: no counterpart candidate in SVOM/GWAC observations
  31. LIGO/Virgo S200224ca: No counterpart candidates in KAIT observations
  32. IPN triangulation of GRB 200221A (short)
  33. Fermi trigger No 604231129: Global MASTER-Net observations report
  34. LIGO/Virgo S200224ca: Subaru/Hyper Suprime-Cam follow-up observations
  35. LIGO/Virgo S200225q : no neutrino counterpart candidate in ANTARES search
  36. LIGO/Virgo S200219ac: No counterpart candidates from Nanshan/NEXT observations
  37. GRB 200224A: Tautenburg observations
  38. GRB 200224A: BOOTES-1 and 1.5m OSN optical observations
  39. GRB 200224A: Swift detection of a burst
  40. Swift GRB200224.14: Global MASTER-Net observations report
  41. GRB 200223A: Fermi GBM Final Real-time Localization
  42. LIGO/Virgo S200219ac: no counterpart candidate in SVOM/GWAC-F30 observations
  43. LIGO/Virgo S200219ac: no counterpart candidate in SVOM/GWAC observations
  44. LIGO/Virgo S200219ac : No significant candidates in TAROT - FRAM - GRANDMA observations.
  45. GRB 200219C: OAJ afterglow confirmation
  46. LIGO/Virgo S200219ac: No counterpart candidates in KAIT observations
  47. GRB 200221A: Fermi GBM Final Real-time Localization
  48. Fermi trigger No 603949983: Global MASTER-Net observations report
  49. Fermi trigger No 603849435: Global MASTER-Net observations report
  50. LIGO/Virgo S200219ac : no neutrino counterpart candidate in ANTARES search
  51. Swift GRB200219.32: Global MASTER-Net observations report
  52. LIGO/Virgo S200213t : No significant candidates in FRAM - OAJ - TAROT - GRANDMA observations
  53. LIGO/Virgo S200213t: CLU/NED Galaxies in the 4-Update Localization Volume
  54. LIGO/Virgo S200213t: Possible host galaxies in the bilby skymap
  55. LIGO/Virgo S200213t: Pre-discovery detections of MASTER OT J044008.76-651302.3
  56. LIGO/Virgo S200213t: Lulin Follow-Up Observations
  57. LIGO/Virgo S200213t: MASTER possible Kilonova candidate in PGC315337
  58. LIGO/Virgo S200213t: P200 Spectroscopy of ZTF20aanakcd/AT2020cmr
  59. LIGO/Virgo S200213t: No counterpart candidates in KAIT observations
  60. LIGO/Virgo S200213t: MANGROVE catalog galaxy ranking
  61. LIGO/Virgo S200208q : No significant candidates in TAROT - FRAM - GRANDMA observations
  62. LIGO/Virgo S200213t : no neutrino counterpart candidate in ANTARES search
  63. LIGO/Virgo trigger S200213t: Possible host galaxies
  64. LIGO/Virgo S200213t: NED Galaxies in the 90% Localization Volume
  65. LIGO/Virgo S200208q: No counterpart candidates in KAIT observations
  66. GRB 200205B: Chilescope optical observations
  67. LIGO/Virgo S200208q : no neutrino counterpart candidate in ANTARES search
  68. Fermi trigger No 602817262: Global MASTER-Net observations report
  69. Fermi trigger No 602731380: Global MASTER-Net observations report
  70. Swift Trigger 954840 is not a GRB
  71. Swift GRB200207.13: Global MASTER-Net observations report
  72. MeerKAT observation of GRB 191221B
  73. Fermi trigger No 602455182: Global MASTER-Net observations report
  74. Re-classification of Fermi GBM triggers 200203137, 200203156/GRB200203A and 200203861
  75. GRB 200131A: Further RATIR Optical Observations
  76. AMON IceCube-HAWC_200202A: MASTER optical inspect
  77. Fermi trigger No 602392636: Global MASTER-Net observations report
  78. GRB 200203A: Fermi GBM Final Real-time Localization
  79. LIGO/Virgo S200128d: no counterpart candidate in SVOM/GWAC observations
  80. LIGO/Virgo S200128d : No significant candidates in FRAM - TAROT - GRANDMA observations
  81. LIGO/Virgo S200129m: Global MASTER-Net observations report
  82. LIGO/Virgo S200129m: Upper limits from IceCube neutrino searches
  83. LIGO/Virgo S200128d: No counterpart candidates in KAIT observations
  84. LIGO/Virgo S200128d : no neutrino counterpart candidate in ANTARES search
  85. LIGO/Virgo S200128d: Coverage and upper limits from MAXI/GSC observations
  86. GRB 200128A: Fermi GBM Final Real-time Localization
  87. Fermi trigger No 601841483: Global MASTER-Net observations report
  88. Fermi trigger No 601729856: Global MASTER-Net observations report
  89. Fermi trigger No 601677816: Global MASTER-Net observations report
  90. LIGO/Virgo S200114f : No significant candidates in TAROT - FRAM - GRANDMA observations
  91. LIGO/Virgo S191222n: AstroSat CZTI upper limits
  92. LIGO/Virgo S200115j: Zwicky Transient Facility search for optical counterparts to Swift X-ray sources
  93. Fermi trigger No 601363105: Global MASTER-Net observations report
  94. Fermi trigger No 601254300: Global MASTER-Net observations report
  95. LIGO/VIRGO S200115j: No obvious candidates from Pan-STARRS2 observations
  96. LIGO/Virgo S191222n: Upper limits from Konus-Wind observations
  97. LIGO/Virgo S200115j : No significant candidates in TAROT - FRAM - GRANDMA observations
  98. LIGO/Virgo S200105ae: More candidates from the Zwicky Transient Facility
  99. LIGO/Virgo S200114f: More candidates from the Zwicky Transient Facility
  100. LIGO/Virgo S200115j: Swift-XRT sources

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