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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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"

7301 results found.

  1. GRB 160910A: Tiled Swift observations
  2. IceCube HESE 160814: MASTER OT J130845.02-323254.9 as the possible source of the high energy neutrino
  3. GRB 160905A: Swift detection of a burst with an optical counterpart
  4. Search for counterpart to IceCube-160814A with ANTARES
  5. GRB 160829A: Swift ToO observations
  6. Swift Trigger 710022 is very likely noise
  7. GRB 160826A: Swift detection of a burst
  8. GRB 160825A: Swift ToO observations
  9. GRB 160824A: Swift detection of a burst
  10. GRB 160821B: GTC follow-up observation
  11. GRB 160821B: WHT afterglow confirmation and redshift of candidate host
  12. GRB 160821B: NOT optical afterglow candidate
  13. GRB 160821B: Swift detection of a short burst
  14. INTEGRAL/SPI-ACS observation of IceCube HESE 128340 58537957
  15. GRB 160816A: RATIR Optical and NIR Afterglow Confirmation
  16. GRB 160816A: confirmed fading with the LT
  17. GRB 160816A: RATIR Optical and NIR Observations
  18. GRB 160816A: LCOGT-FTN optical candidate
  19. GRB 160816A: Swift ToO observations
  20. GRB 160815A: Swift detection of a burst
  21. INTEGRAL/SPI-ACS and IBIS_VETO search for prompt gamma-ray counterpart of IceCube-160806A
  22. IceCube 160806A EHE Neutrino Candidate Event
  23. Swift Trigger 707545 is likely 4U 1850-03/GS1843-02
  24. Swift Trigger 707517 is probably not a GRB
  25. IceCube-160731A: Konus-Wind limits
  26. Search for counterpart to IceCube-160731A with ANTARES
  27. GRB 160804A: TNG optical observations, afterglow fading and candidate host galaxy
  28. IceCube-160731A: iPTF P48 Observations
  29. GRB 160801A: Swift detection of a burst
  30. Trigger 706396: Swift detection of a short burst from PSR 1119-6127
  31. GRB 160716A: Swift detection of a burst
  32. Swift Trigger 704444 is probably not an astrophysical event.
  33. Swift Trigger 704327: a possible GRB
  34. GRB 160712A: Swift/UVOT Upper Limits
  35. GRB 160712A: Initial Swift/UVOT observations
  36. GRB 160709A: Tiled Swift observations
  37. GRB 160705B: LT optical candidate
  38. GRB 160705B: Swift detection of a burst
  39. GRB 160703A: Swift detection of a burst
  40. GRB 160629A: Swift ToO observations
  41. GRB 160630A: Swift detection of a burst
  42. Swift Trigger 701668 is probably not an astrophysical event
  43. Trigger 701590: Swift detection of a bright outburst from SGR 1935+2154
  44. GRB 160625B: Tiled Swift observations
  45. GRB 160624A: Swift detection of a short burst
  46. Trigger 701182: Swift detection of SGR 1935+2154
  47. GRB 160623A: Swift ToO observations
  48. GRB 160622A: Swift detection of a possible short GRB or a new SGR
  49. LIGO/Virgo G197392 / LVT151012: Sky maps and other data available in LOSC
  50. GRB 160612A: Swift ToO observations
  51. Trigger 689956: Swift detection of a source near the Galactic center
  52. GRB 160607A: GROND confirmation of the afterglow
  53. GRB 160607A: candidate optical afterglow from the NOT
  54. GRB 160607A: Swift detection of a bright burst
  55. GRB 160530A: further Swift-XRT follow-up observations
  56. Trigger 689353: Swift detection of a transient near Sgr A*
  57. GRB160601A: Gemini Imaging
  58. GRB160601A: NOT detection of an afterglow candidate
  59. GRB 160530A: Swift follow-up and X-ray afterglow candidate
  60. GRB 160601A: Swift detection of a short hard burst
  61. GRB 160530A: Tiled Swift observations
  62. GRB 160525B: Swift detection of a burst
  63. GRB 160521B: Theoretical estimate of the redshift and urgent need for further x-ray observations
  64. Another Swift detection of SGR 1935+2154 (trigger #687124)
  65. Swift detection of SGR 1935+2154
  66. GRB 160521B: Swift ToO observations
  67. Trigger 686761: Swift detection of a bright burst from SGR 1935+2154
  68. Trigger 686443: Swift detection of SGR 1935+2154
  69. GRB 160509A: DCT Imaging / Afterglow Confirmation
  70. GRB 160509A: VLA Detection
  71. GRB 160509A: Swift/UVOT Upper Limit
  72. GRB 160509A Gemini North candidate afterglow
  73. GRB 160509A: optical observations
  74. GRB 160509A: Tiled Swift observations
  75. GRB 160506A: Swift detection of a burst
  76. IceCube-160427A: iPTF Observations
  77. GRB 160504A: Swift detection of a burst
  78. ICECUBE-160427A : Pan-STARRS imaging and optical transients in the field
  79. GRB 160501A: Swift detection of a burst
  80. ICECUBE-160427A neutrino candidate event: updated direction information
  81. Fermi/LAT search for counterpart to the IceCube event 67093193 (run 127853)
  82. GRB 160422A: XRT Afterglow Confirmation
  83. LSGT observation of GRB 160425A
  84. GRB 160422A: Swift/UVOT Afterglow Confirmation
  85. GRB 160425A: Swift detection of an unusual burst with an optical afterglow
  86. LIGO/Virgo G197392 / LVT151012: Identification of a GW CBC Candidate
  87. GRB 160424A: Swift/UVOT Upper Limit
  88. GRB 160422A: Swift-XRT afterglow detection
  89. GRB 160422A: Swift/UVOT Candidate Afterglow
  90. GRB 160422A: Swift ToO observations
  91. GRB 160417A: Swift detection of a burst with an optical counterpart
  92. GRB 160411A - Gemini-S afterglow candidate
  93. GRB 160410A: further NOT optical observations
  94. GRB 160412A: Swift detection of a burst
  95. GRB 160409A: Swift ToO observations
  96. GRB 160410A: Swift detection of a (possibly-short) burst with an optical counterpart
  97. GRB 160408A: Swift detection of a short burst
  98. GRB 160401A: Swift ToO observations
  99. GRB 160327A: Swift detection of a burst
  100. GRB 160325A: afterglow confirmation

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