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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"

8521 results found.

  1. LIGO/Virgo S191105e: Not observable by CALET
  2. LIGO/Virgo S191105e : no neutrino counterpart candidate in ANTARES search
  3. LIGO/Virgo S191105e: No counterpart candidates in HAWC observations
  4. LIGO/Virgo S191105e: upper limits from AGILE/GRID observations
  5. LIGO/Virgo S191105e: Upper limits from Fermi-GBM Observations
  6. LIGO/Virgo S191105e: Identification of a GW compact binary merger candidate
  7. LIGO/Virgo S191105e: Upper limits from IceCube neutrino searches
  8. GRB 191106A: Swift detection of a burst
  9. Fermi GBM GRB 191104C (trigger 594592184 / 191104854) is not a GRB
  10. Fermi GBM GRBs 191104 A, B, C and triggers 594534420/191104185 and 594563923/191104527 are not GRBs
  11. GRB 191101A: Swift detection of a burst
  12. GRB 191031D: Swift detection of a short hard burst
  13. GRB 191031C: Swift detection of a burst
  14. Swift Trigger 931484 is not a GRB
  15. Swift Trigger 931384: possible GRB 191025A
  16. GRB 191024A: Swift detection of a burst
  17. GRB 191019A: NOT optical afterglow and host association confirmation
  18. HAWC-191019A: No Neutrino Counterpart detected with ANTARES
  19. GRB 191019A: NOT optical spectroscopy of candidate counterpart
  20. GRB 191017B: Swift detection of a burst
  21. GRB 191016A: RATIR Optical and NIR Observations
  22. GRB 191011A: MASTER OT retraction.
  23. GRB 191011A: GROND Detection of the Optical/NIR afterglow
  24. GRB 191011A: Swift detection of a burst with an optical counterpart
  25. LIGO/Virgo S190930t: Continued Swift observations of AT2019sbk
  26. Fermi/GBM observation of a bright burst from magnetar SGR 1935+2154
  27. LIGO/Virgo S190930s: no counterpart candidate in the SVOM/GWAC observations
  28. LIGO/Virgo S190930s: Updated Sky Localization
  29. GRB 191004B: Swift detection of a burst with an optical counterpart
  30. LIGO/Virgo S190930t: J-GEM follow-up observation for Swift J221951-484240
  31. LIGO/Virgo S190930t: Continued Swift/UVOT observations of Swift J221951-484240
  32. IceCube-191001A: HAWC follow-up
  33. Fermi-LAT Gamma-ray Observations of IceCube-191001A
  34. IceCube-191001A: Candidate Counterparts with the Zwicky Transient Facility
  35. IceCube-191001A: Not observable by Fermi-GBM
  36. GRB 191001A: Swift ToO observations
  37. LIGO/Virgo S190930t: Candidates from ATLAS observations and constraints on AT2019rpr and AT2019rpn
  38. LIGO/Virgo S190930t: J-GEM follow-up observations for AT2019rpj
  39. GRB 191001A: KAIT Optical Upper Limit
  40. GRB 191001A: RATIR Optical and NIR Observations
  41. LIGO/Virgo S190930t: Lulin Follow-up Observations of AT2019rpn and AT2019rpj
  42. IceCube-191001A - IceCube observation of a high-energy neutrino candidate event
  43. GRB 191001A: DDOTI Optical Counterpart Candidate
  44. LIGO/Virgo S190924h: Correction to GCN 25905, updated sky localization for S190924h
  45. LIGO/Virgo S190828h: Updated Sky Localization
  46. LIGO/Virgo S190930t: Transient found in Swift/UVOT counterpart search
  47. LIGO/Virgo S190930t: Candidates from the Zwicky Transient Facility
  48. LIGO/Virgo S190930t: Upper limits from Fermi-GBM Observations
  49. LIGO/Virgo S190930s: Upper limits from Fermi-GBM Observations
  50. LIGO/Virgo S190930t: No counterpart candidates in HAWC observations
  51. LIGO/Virgo S190930s: no counterpart candidates in AGILE-GRID observations
  52. LIGO/Virgo S190928c: Retraction of GW unmodeled transient candidate
  53. LIGO/Virgo S190930t : no neutrino counterpart candidate in ANTARES search
  54. LIGO/Virgo S190930s : no neutrino counterpart candidate in ANTARES search
  55. LIGO/Virgo S190930t: Identification of a GW compact binary merger candidate
  56. LIGO/Virgo S190930t: Upper limits from IceCube neutrino searches
  57. LIGO/Virgo S190930s: Upper limits from IceCube neutrino searches
  58. LIGO/Virgo S190930s: Identification of a GW compact binary merger candidate
  59. LIGO/Virgo S190828j: Updated Sky Localization
  60. GRB 190926A: KAIT Optical Upper Limit
  61. GRB 190926A: Swift detection of a burst
  62. LIGO/Virgo S190924h: Not observable by CALET
  63. LIGO/Virgo S190924h: Upper limits from Fermi-GBM Observations
  64. LIGO/Virgo S190924h : no neutrino counterpart candidate in ANTARES search
  65. IceCube-190922B: Upper limits from a search for additional neutrino events in IceCube
  66. IceCube-190922A: Upper limits from a search for additional neutrino events in IceCube
  67. LIGO/Virgo S190924h: Identification of a GW compact binary merger candidate
  68. LIGO/Virgo S190924h: Upper limits from IceCube neutrino searches
  69. IceCube-190922B - HAWC follow-up
  70. IceCube-190922B: Identification of a Candidate Supernova from the Zwicky Transient Facility
  71. LIGO/Virgo S190923y: Upper limits from Fermi-GBM Observations
  72. LIGO/Virgo S190814bv: Chandra X-ray non-detection of ASKAP J005547-270433 / AT2019osy
  73. LIGO/Virgo S190923y: Upper limits from AGILE-GRID observations
  74. LIGO/Virgo S190923y : no neutrino counterpart candidate in ANTARES search
  75. LIGO/Virgo S190923y: Identification of a GW compact binary merger candidate
  76. LIGO/Virgo S190923y: No counterpart candidates in HAWC observations
  77. LIGO/Virgo S190923y: Upper limits from IceCube neutrino searches
  78. IceCube-190922B: Upper limits from Fermi-GBM Observations
  79. IceCube-190922A: Upper limits from Fermi-GBM Observations
  80. IceCube-190922B - IceCube observation of a high-energy neutrino candidate event
  81. IceCube-190922A - HAWC follow-up
  82. IceCube-190922A - IceCube observation of a high-energy neutrino candidate event
  83. GRB 190919B: Swift ToO observations
  84. LIGO/Virgo S190814bv: SOAR spectroscopy of AT2019nte host galaxy
  85. LIGO/Virgo S190828l: Updated Sky Localization
  86. LIGO/Virgo S190910h: Updated Sky Localization
  87. HAWC-190916A: IceCube neutrino search
  88. LIGO/Virgo S190915ak: Updated Sky Localization
  89. HAWC-190916A: Upper limits from Fermi-GBM Observations
  90. LIGO/Virgo S190915ak: Upper limits from Fermi-GBM Observations
  91. LIGO/Virgo S190915ak : no neutrino counterpart candidate in ANTARES search
  92. LIGO/Virgo S190915ak: Upper Limits from AGILE-GRID observations
  93. LIGO/Virgo S190915ak: No counterpart candidate in AGILE-MCAL observations
  94. LIGO/Virgo S190915ak: Upper limits from IceCube neutrino searches
  95. LIGO/Virgo S190915ak: Identification of a GW compact binary merger candidate
  96. LIGO/Virgo S190814bv: No counterpart candidate after completion of GRAWITA VST-ESO PARANAL transient survey.
  97. LIGO/Virgo S190910d: MASTER previous detection of Gaia19eba/AT2019qam
  98. LIGO/Virgo S190910d: Gaia Photometric Alerts transient candidate
  99. LIGO/Virgo S190910d: WHT spectroscopy of ZTF19abyfhov, ZTF19abyfhaq, ZTF19abyfbii
  100. LIGO/Virgo S190910d: Updated Sky Localization

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