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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"

28052 results found.

  1. GRB010427, Gamma Ray Observations
  2. SGR 1900+14: No evidence of extended X-ray emission
  3. SGR 1900+14 : RXTE observations
  4. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  5. SGR 1900+14: Correction to GCN 1049
  6. GRB 010222 /corrections to VBT data
  7. Millimeter observation of SGR 1900+14
  8. SGR 1900+14: Detection of extended X-ray emission
  9. SGR 1900+14, Chandra observations
  10. SGR1900+14, I-band observations
  11. GRB010412, field photometry
  12. Giant flare from SGR1900+14
  13. GRB 010326b Optical Observations
  14. GRB010412: BeppoSAX GRBM and WFC observations
  15. GRB010324, revised field photometry
  16. REVISED LOCATION OF GRB010326A
  17. GRB 980326: Late-time HST/STIS observations
  18. GRB010324, field photometry
  19. GRB010326B, field photometry
  20. GRB010326, field photometry
  21. GRB010220, field photometry
  22. Further Optical Observations of GRB 010324
  23. GRB010222, CXO X-ray observations
  24. GRB010324, optical observations
  25. GRB010326B: Localization by HETE (2nd GRB for this date)
  26. GRB 010326 optical observations
  27. GRB010326: Refined Localization by HETE
  28. GRB010326: Localization by HETE
  29. Optical Observations of GRB 010324
  30. GRB010222, late-time optical observation
  31. Support extension to the BeppoSAX mission
  32. GRB 010222 - HEGRA GeV/TeV Observations
  33. GRB010222: Chandra X-ray Observatory Observation
  34. GRB010222: Sub-millimeter vanishing act
  35. GRB010222 - Optical observation
  36. GRB 010222, Optical Observations
  37. GRB010222 - Optical observation
  38. GRB 010222: High-Resolution Keck Spectroscopy
  39. GRB 010214, I-band data
  40. GRB 010222
  41. GRB010222 further R-band photometry
  42. GRB010222: R-band data
  43. GRB 010222: Keck Spectroscopy
  44. GRB010214, field photometry
  45. GRB010222, field photometry
  46. GRB010222 further R-band photometry
  47. GRB010222, possible increase of optical decay slope
  48. GRB 010222 Kyoto optical observation
  49. GRB010222 R-BAND OBSERVATION
  50. GRB010214 follow-up from Hanle
  51. GRB 010222: Near-IR Observations
  52. GRB 010222: Optical Observations
  53. GRB010222: Optical decay slope
  54. GRB 010214, Optical Observations
  55. GRB010222, radio observations
  56. GRB010222, optical observations
  57. GRB010222: BeppoSAX/NFI Observations
  58. GRB010214B,Gamma Ray Observations
  59. GRB 010220, simultaneous optical observations
  60. GRB010220: BeppoSAX WFC and GRBM preliminary data
  61. GRB010214, candidate optical afterglow
  62. GRB010214, optical observations
  63. GRB010214: BeppoSAX WFC and GRBM preliminary data
  64. GRB 010214: X-Ray afterglow
  65. GRB 010214 optical observation
  66. GRB010213, Radio Observations
  67. J-Band Observation of GRB 010214.
  68. GRB010213, Near-IR observations
  69. Possible InfraRed Transient of GRB 010214.
  70. GRB 010214, optical observations
  71. GRB010213 detected by HETE
  72. IPN Status Report
  73. HETE Status
  74. IPN/RXTE TRIANGULATION OF GRB010126
  75. GRB010126 Optical Observations
  76. IPN TRIANGULATION OF GRB010126
  77. Optical Observations of GRB 001018 at Keck
  78. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  79. Optical observations of GRB 001018 with JCAM
  80. IPN TRIANGULATION OF GRB010115
  81. IPN TRIANGULATION OF GRB010109
  82. IPN TRIANGULATION OF GRB010109
  83. IPN triangulation of GRB010104
  84. IPN triangulation of GRB010103
  85. H band observation of GRB 001212
  86. IPN triangulation of GRB001219
  87. GRB 001212 Optical Observation
  88. GRB 001212 Optical Observation
  89. GRB 001212 possible OA in 2MASS
  90. IPN triangulation of GRB001212
  91. Confirmation of IPN position for GRB001204
  92. IPN triangulation of GRB001204 (short/hard)
  93. GRB001120, optical observations
  94. WSRT 4.8 GHz observations of GRB001109
  95. IPN triangulation of GRB001120
  96. GRB 001109: deep JHK upper limits
  97. GRB 001109 X-ray afterglow with BeppoSAX
  98. CORRECTION to XMM-Newton observation of GRB001025
  99. GRB001109, Radio observations
  100. GRB001105 BVRI field photometry correction

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