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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"

5051 results found.

  1. GRB021004: Upper limits from recent and historical observations
  2. XRF 020903: Supernova
  3. IPN annulus for GRB020923
  4. GRB020903(=H2314): An X-Ray Flash Localized by HETE
  5. INTEGRAL GRBs added to GCN
  6. GRB 020812: early time optical observation at Ouda Station
  7. GRB020813: optical and NIR observations
  8. GRB 020813: addendum to GCN 1498
  9. GRB020812: NIR observations
  10. GRB020813, optical observations
  11. Further refinement to IPN error box for GRB020531
  12. GRB020625 (=H2081): A Long Burst Localized by HETE
  13. GRB020531: Second epoch Chandra observations
  14. GRB020531 Optical observations with TAROT
  15. GRB020531: Observations with the Chandra X-ray Observatory
  16. Refined IPN error box for GRB020531
  17. IPN triangulation of the short, hard GRB020531 (=H2042)
  18. GRB020321 : Optical observations.
  19. GRB 020124: Optical observations
  20. GRB 020409: Optical observations
  21. GRB 020409: No Evidence for an Optical Afterglow
  22. GRB 020331 Kyoto observation on March 31
  23. GRB 020409
  24. GRB020124 optical observations with RIBOTS/RIMOTS
  25. Short RXTE/ASM transient 020406; may be a GRB
  26. GRB 020321, Radio Observations
  27. GRB 020321: Optical observations
  28. GRB 020322 optical observations
  29. GRB020317 : Near IR Observations from Mt Abu Observatory
  30. GRB 020317 : KISO Optical Observations
  31. GRB 020317: Optical observations
  32. GRB011130 (XRF011130) Second Epoch Chandra Observations
  33. IPN detection and localization of Cygnus X-1 flares
  34. IPN Upper Limits to a GRB Associated With SN2002ap
  35. GRB020124: Optical observations
  36. GRB 020124: Optical observations
  37. GRB020124(=H1896): Localization of a Long GRB by HETE
  38. GRB011130 (=XRF011130): Further analysis of Chandra Target of
  39. GRB 011121
  40. GRB011030, optical observation
  41. GRB010923 as seen by BeppoSAX GRBM
  42. GRB010923(=H1764): A Short Duration GRB Detected by HETE
  43. GRB001109, Host Galaxy Astrometry
  44. GRB000926, Host Galaxy Observations
  45. GRB001109, Host Galaxy Spectroscopic Observations
  46. BeppoSAX/GRBM detection of GRB010728
  47. SGR1900+14: Second Burst Localized by HETE
  48. SGR1900+14: A Burst Localized by HETE
  49. Millimeter observation of SGR 1900+14
  50. GRB010324: BeppoSAX/GRBM data
  51. GRB 010214, I-band data
  52. Sub-millimeter Excess/GRB 010222
  53. GRB 010220: Near-IR Observations
  54. GRB 010222: Near-IR Observations
  55. GRB010214, optical observations
  56. J-Band Observation of GRB 010214.
  57. Possible InfraRed Transient of GRB 010214.
  58. GRB010214 Optical Observation
  59. GRB & BeppoSAX: ground operations restored back to 24 hrs a day
  60. IPN triangulation of GRB001219
  61. GRB 001212 Optical Observation
  62. GRB 001212 Optical Observation
  63. IPN triangulation of GRB001212
  64. GRB 001025B, I-band observations
  65. IPN TRIANGULATION OF GRB001020
  66. GRB 000926 : the host galaxy
  67. IPN triangulation of GRB001005
  68. J and K band observations of GRB 000926
  69. GRB000830, TNG B-band observations
  70. GRB000830: Optical observations
  71. Updated IPN coordinates for GRB000801
  72. IPN localization of GRB000801
  73. IPN localization of GRB000727
  74. GRB 990712: Late time HST/STIS Observations
  75. GRB000630: Optical observations
  76. GRB 000620: J-band observations
  77. GRB 000615: NIR further observations
  78. GRB 000615: NIR observations
  79. GRB000615: BeppoSAX GRB Alert
  80. IPN localization of GRB000429
  81. GRB000418, near-infrared observations
  82. BeppoSAX GRB000424
  83. IPN error box for GRB000418
  84. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  85. Budget cuts in BeppoSAX operations: impact on GRB observations
  86. GRB000408 [IPN Position]
  87. GRB000301C - B and R photometry
  88. GRB 000301C: HST/STIS CCD Imaging of the field
  89. HST Observations of GRB 990712
  90. SAX_WFC_GRB_NOTICE
  91. GRB 000131 Optical Observations
  92. IPN error boxes for GRB991229
  93. IPN error box for GRB991216
  94. GRB991216, optical observations
  95. GRB991208, optical observations
  96. GRB 991106, optical observations
  97. GRB991106, near-infrared observations
  98. GRB 991106, radio observations
  99. GRB 991014 - BeppoSAX NFI observations
  100. IPN localization of GRB990907

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