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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"

28051 results found.

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

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