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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"

3995 results found.

  1. SGR 1900+14, Chandra observations
  2. Chandra Observations of SGR 1900+14
  3. SGR1900+14, I-band observations
  4. GRB 980326: Late-time HST/STIS observations
  5. GRB 010214, I-band data
  6. GRB010214 Optical Observation
  7. GRB010126 optical observations
  8. Optical Observations of GRB 001018 at Keck
  9. IPN triangulation of GRB001219
  10. GRB 001109: deep JHK upper limits
  11. IPN TRIANGULATION OF GRB001105
  12. IPN TRIANGULATION OF GRB001020
  13. GRB 000926 Chandra Observation
  14. GRB000926 K'-band Observation
  15. HST/STIS observations of the host galaxy of GRB 980329
  16. SGR 1806-20 burst activity
  17. IPN localization of GRB000730B
  18. IPN localization of GRB000730B
  19. GRB 990510: Possible detection of a host galaxy
  20. GRB 990510 Host Galaxy Discovery
  21. GRB 990712: Late time HST/STIS Observations
  22. GRB 000630: Detection of the Optical Afterglow
  23. GRB000616 [IPN Position]
  24. GRB 000418: Detection of the Host Galaxy
  25. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  26. GRB000529: BeppoSAX WFC position
  27. GRB000528: BeppoSAX GRBM observations
  28. GRB000419 [IPN Position]
  29. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  30. GRB 000326: Optical Observations
  31. GRB 000301C, Optical Observation
  32. GRB000301C
  33. GRB 000301C : Optical Candidate
  34. GRB000226 [IPN Position]
  35. HST Observations of GRB 990712
  36. IPN annulus for GRB000214
  37. GRB000126, optical observations
  38. IPN localization of GRB000126
  39. GRB991216 late optical observation
  40. BEPPOSAX GRBM Localization of GRB991226
  41. IPN error boxes for GRB991229
  42. IPN localization of GRB991226
  43. IPN localization of GRB991208
  44. IPN localization of GRB991014 - CORRECTION
  45. IPN localization of GRB991014
  46. BATSE GRB trigger criteria
  47. GRB 990712 Late Optical Decay and Host Galaxy
  48. GRB 990712, Optical Observation
  49. GRB 990712
  50. IPN localization of GRB990705
  51. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  52. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  53. GRB 990510: optical observations
  54. GRB 990510: optical observations
  55. GRB990510: X-ray afterglow
  56. GRB 990510: optical observation
  57. GRB 990510: Broad Band Break
  58. GRB990510: optical observation
  59. GRB 990510 Optical Observations
  60. GRB 990510 optical observations
  61. GRB990510 optical observations
  62. GRB990510
  63. GRB 990510 optical observations
  64. GRB 990510 optical observations
  65. GRB 990510 optical observations
  66. IPN localization of GRB990510
  67. New IPN/RXTE error box for GRB990506
  68. GRB990308 not a new SGR
  69. GRB990308, Possible new SGR~0209+70
  70. GRB 990123: Discovery of the Probable Host Galaxy
  71. Possible identification of SN1999E with GRB980910
  72. GRB 981226: radio variable
  73. GRB 981226 Optical Observations
  74. GRB981226, sub-millimeter observations
  75. GRB 981226
  76. GRB 981226 optical observations
  77. Optical Observations of GRB981226
  78. GRB 981226 - Infrared Observations
  79. SGR1900+14, BeppoSAX-GRBM observations
  80. SGR1627-41
  81. SGR1627-41, RXTE/ASM observations
  82. Reduced error box of SGR 1627-41
  83. SGR 1627-41
  84. Discovery of a new SGR source, SGR1627-41
  85. GRB980613 observations from Palomar
  86. SGR 1900+14
  87. SGR1900+14
  88. SGR1900+14
  89. BATSE on-board GRB trigger change
  90. GRB980329 IPN annulus
  91. Optical Observations of GRB 970508
  92. IRAS 18119-1342 and the possible new SGR
  93. Possible new SGR from US Naval Observatory
  94. RXTE Observations of SGR 1814-13
  95. GRB 970828: Palomar Observations

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