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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"

35427 results found.

  1. GRB020317 BVRI field photometry
  2. GRB011211 revised BVRI field photometry
  3. GRB020305 BVRI field photometry
  4. GRB020322 BVRI field photometry
  5. GRB 020322 optical observations
  6. GRB 020322 optical observation
  7. GRB020317 : Near IR Observations from Mt Abu Observatory
  8. GRB 020322: Optical Sources and Improved Astrometry
  9. GRB020322, optical observations
  10. GRB 020322: Optical candidate
  11. GRB020322: BeppoSAX/NFI Observations
  12. Bepposax GRB020322 The second springtime BSAX GRB
  13. GRB 020321: Optical observations
  14. GRB 011121: Fourth Epoch of HST Imaging
  15. GRB020317: optical observations
  16. GRB020321 optical observations
  17. GRB020321: BeppoSAX/NFI Observations
  18. GRB020321: a faint BeppoSAX detection
  19. GRB 020317 : KISO Optical Observations
  20. BeppoSAX ALERT: GRB020321, the "Springtime Burst"
  21. GRB020317 (=H1959): Localization by HETE of a Low Fluence GRB
  22. GRB 020305: Optical Observations
  23. GRB020317, optical observations
  24. GRB 020317: Optical observations
  25. GRB 011121: Third HST Epoch
  26. GRB020305: Properties of the Candidate Optical Afterglow
  27. GRB 011121: HST Observations reveal an intermediate-time multicolor
  28. GRB011121, possible supernova association
  29. GRB011130 (XRF011130) Second Epoch Chandra Observations
  30. GRB020305: Subaru Optical Observations
  31. GRB 020305: Optical observations
  32. XRF/GRB 011030 Images
  33. XRF/GRB 011030: Detection of the Probable Host Galaxy
  34. GRB 020305: Candidate optical afterglow
  35. Type Ic SN2002bl (SN/GRB?) Radio Observations
  36. GRB020305: Optical Observations
  37. IPN triangulation of GRB020305 (HETE 1939)
  38. GRB020305 (=H1939): Localization of a GRB by HETE
  39. GRB 020305: Optical observations
  40. HST Imaging of the afterglow and host of GRB 011121
  41. GRB 010921: HST Observations
  42. IPN detection and localization of Cygnus X-1 flares
  43. GRB020127: Further VLA Observations of Possible Counterparts
  44. IPN detection of further SGR1900+14 activity
  45. SGR1900+14 activity
  46. IPN/HETE Detection of Bursts from SGR1900+14
  47. IPN Upper Limits to a GRB Associated With SN2002ap
  48. GRB020124 BVRI field photometry
  49. GRB020127: Comparison of Chandra Epochs and Identification of Possible Counterparts
  50. SN2002ap (SN/GRB?) Echelle spectra
  51. SN2002ap (SN/GRB?) optical spectrographic observations
  52. GRB020127 Optical Observations
  53. SN 2002ap (SN/GRB?)
  54. SN2002ap (SN/GRB?) UBVRI Field Photometry
  55. GRB020127: Chandra Observations and Prospective Counterparts
  56. pre-SN2002ap (SN/GRB?) imaging of M74
  57. SN 2002ap (hypernova / GRB ??): special list on VSNET
  58. Type Ib/c SN2002ap (SN/GRB?)
  59. Type Ib/c SN2002ap (SN/GRB?) Radio Observations
  60. GRB020124, optical observations
  61. GRB020127: Optical observations
  62. GRB 020127, I-band observations starting 3.14-hr after the event
  63. IPN detection of further activity from SGR1806-20
  64. IPN triangulation of GRB020127 (=H1902)
  65. GRB010921 Optical Observations
  66. GRB020127(=H1902): Localization of a Double-Peaked GRB by HETE
  67. GRB020124: Optical observations
  68. VLT observations of GRB 020124: The fading optical/near-infrared afterglow
  69. GRB020124: Optical observations
  70. GRB 020124: Optical observations
  71. GRB 020124 Optical Observations
  72. IPN triangulation of GRB020124 (HETE 1896)
  73. IPN observations of SGR1806-20
  74. GRB 020124: Optical afterglow
  75. GRB020124(=H1896): Localization of a Long GRB by HETE
  76. GRB optical counterpart candidate in GCN 1217 is M dwarf
  77. Possible optical counterpart to a GRB
  78. GRB011212, Optical Observations
  79. GRB 011211: Detection of the Probable Host Galaxy
  80. GRB 011130 and GRB 011212 - Milagro GeV/TeV Observations
  81. GRB 011211, spectrum and optical photometry
  82. GRB 011130: Optical Observations of X-ray and Radio Sources
  83. GRB 011130, Radio/X-ray Comparison
  84. GRB 011212: optical observation at Asiago
  85. GRB 011211: Evidence for an Optical Break
  86. GRB 011211: TNG Spectroscopic Observations
  87. optical follow-up of GRB(XRF) 011211
  88. GRB 011212: optical observation at Oslo (relayed)
  89. GRB 011211: Optical Spectroscopy
  90. GRB 011211, Optical Observations
  91. GRB011212, BVRI field photometry
  92. GRB011211, BVRI field photometry
  93. GRB011212: Optical observations
  94. GRB 011211: BVRi-band photometry
  95. GRB011212 (=H10001): An X-Ray Rich GRB Detected by HETE
  96. Fading of the optical source associated of XRF 011211
  97. GRB 011211 Optical Observations: Likely Afterglow
  98. BeppoSAX Alert: GRB011211(=XRF011211)
  99. GRB 011130: Optical Observations of Chandra Sources
  100. GRB 011130: Optical Observations of Chandra sources

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