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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"

21455 results found.

  1. XRB 080109/SN 2008D:PAIRITEL NIR observations and t_0 from Swift
  2. XRF 080109 in NGC2770: Detectable Superluminal Motion
  3. XRF in NGC 2770: Search for X-ray periodicity
  4. Refined Swift-XRT analysis of the transient in NGC 2770
  5. Refined Swift UVOT Analysis of SN 2008D (Transient in NGC 2770)
  6. Swift UVOT Observations of the X-ray transient in NGC 2770
  7. Early OT detection of XRF in NGC 2770 in Asiago frames
  8. Bright X-ray Transient in NGC 2770 - A low-luminosity XRF?
  9. GRB 071227: Suzaku WAM observation of the prompt emission
  10. GRB 071227: optical afterglow
  11. Further Swift-BAT analysis of GRB 071227
  12. Konus-Wind observation of GRB 071227
  13. GRB 071227: Swift-XRT refined analysis
  14. GRB 071227: VLT probable redshift of the candidate host galaxy
  15. GRB 071227: Magellan observations
  16. GRB071227: Swift/UVOT refined analysis
  17. GRB 071227: REM NIR and Optical observations
  18. Swift-BAT refined analysis of short GRB 071227
  19. GRB 071227: Swift detection of a burst
  20. GRB 070429B: Possible UVOT Detection of an Optical Afterglow
  21. Swift-BAT trigger 298308 is not a GRB
  22. GRB 071208?: Swift detection of a possible burst
  23. GRB 071129, Swift-BAT refined analysis
  24. GRB 071129: Swift detection of a burst
  25. Disregard the "GRB 071126" position
  26. GRB 071126: Enhanced Swift-XRT position
  27. VLA radio detection of GRB 071122
  28. GRB071122: Swift/UVOT Observations
  29. GRB071104: NIR Afterglow Candidate at TNG
  30. GRB 071122, Swift-BAT refined analysis
  31. GRB 071122 Swift XRT position update sent in error.
  32. GRB 071122 Swift-XRT refined analysis
  33. GRB 071122: P60 Optical Afterglow Candidate
  34. GRB 071122: ROTSE-III Optical Limits
  35. GRB 071122: Swift detection of a burst
  36. GRB071118 MITSuME OAO optical observation
  37. GRB 071117: VLT observations and probable redshift
  38. Swift/UVOT observations of GRB071118
  39. GRB 071117: Swift-XRT revised position
  40. Konus-Wind and Konus-A observations of GRB 071117
  41. Swift XRT follow-up observations of GRB071008
  42. Swift/UVOT upper limits for GRB 071117
  43. GRB071118: Swift XRT refined analysis
  44. GRB 071117: Gemini Optical Afterglow Discovery
  45. GRB 071118, Swift-BAT refined analysis
  46. GRB 071117: TAROT La Silla observatory optical observations
  47. GRB 071118: Swift detection of a burst
  48. GRB 071117: Gemini Observations
  49. GRB 071117: Las Campanas optical observations
  50. GRB 071117: Swift-XRT refined analysis
  51. GRB 071117, Swift-BAT refined analysis
  52. GRB 071117: Swift/XRT position
  53. GRB 071117: Initial Swift/UVOT observations
  54. GRB 071117: Swift detection of a bright burst
  55. Swift detection of MXB 0656-072
  56. VLA radio upper limit on GRB 071112C
  57. ATCA radio observations of short hard burst GRB 071112B
  58. Correction to the Swift-BAT Transient Identification (trigger=296683)
  59. GRB 071112C: Swift-BAT refined analysis
  60. GRB 071112C: Swift/UVOT observations
  61. GRB 071112C: Swift XRT refined analysis
  62. Swift UVOT upper limits of GRB071112B
  63. GRB 071112B: Gemini Optical Imaging
  64. GRB 071112B: Swift-XRT preliminary analysis
  65. GRB 071112B, Swift-BAT partial refined analysis of the SHB
  66. GRB 071112C: Palomar Pre-Imaging
  67. Swift-BAT trigger 296491 is not a GRB
  68. GRB 071112C: TAROT Calern observatory optical observations
  69. Swift XRT follow-up observations of GRB071028B
  70. GRB 071112C: ROTSE-III Confirmation of Optical Counterpart
  71. GRB 071112B: ROTSE-III Rapid Optical Limits
  72. GRB 071112C: Swift detection of a burst with an optical counterpart
  73. GRB 071112B: Swift detection of a short hard burst
  74. GRB 071112: Swift detection of a possible burst
  75. GRB071109: Super-LOTIS observations
  76. VLA IInd observation of INTEGRAL burst GRB 071109
  77. Swift/UVOT initial analysis of GRB071109
  78. GRB 071109: further Swift-XRT analysis
  79. No radio detection at Swift-XRT position
  80. GRB 071109: Swift-XRT possible X-ray counterpart
  81. GRB 071104: Swift-XRT Team Refined Analysis
  82. GRB 071104: Possible Swift UVOT Afterglow Candidate
  83. GRB 071104: Swift-XRT position
  84. Swift XRT and UVOT observations of GRB071028B
  85. GRB 071101, Swift-BAT refined analysis
  86. GRB 071101: Swift-XRT Team refined analysis
  87. GRB071101: Optical and NIR upper limits by KANATA
  88. GRB0711101: Two new source from Xinglong TNT observation
  89. GRB 071101: TAROT Calern observatory optical observations
  90. GRB 071101: Swift XRT position
  91. GRB 071101: BOOTES-2 prompt optical observations
  92. GRB 071101: a nearby galaxy
  93. GRB 071101: Swift detection of a burst
  94. GRB 071031, Swift-BAT refined analysis
  95. GRB 071031: Swift/UVOT detection of afterglow
  96. GRB 071031: Swift-XRT Team refined analysis
  97. GRB 071031: GROND detection in all bands
  98. GRB 071031: Swift detection of a burst with an optical counterpart
  99. GRB 071028B Swift-BAT detection of a burst
  100. GRB 071028: SARA observations of variable source

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