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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"

35433 results found.

  1. IPN/RXTE TRIANGULATION OF GRB010126
  2. GRB 010119, optical observations
  3. GRB010119: Optical observations
  4. Optical Observations of GRB 001018 at Keck
  5. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  6. Optical observations of GRB 001018 with JCAM
  7. IPN TRIANGULATION OF GRB010115
  8. IPN TRIANGULATION OF GRB010109
  9. GRB010103, optical observations
  10. IPN triangulation of GRB010104
  11. IPN triangulation of GRB010103
  12. GRB 001204: Ks observations
  13. H band observation of GRB 001212
  14. GRB & BeppoSAX: ground operations restored back to 24 hrs a day
  15. IPN triangulation of GRB001219
  16. GRB 001212 Optical Observation
  17. GRB 001212 Optical Observation
  18. GRB 001212 optical observation
  19. GRB 001212 possible OA in 2MASS
  20. GRB 001212 possible OA
  21. IPN triangulation of GRB001212
  22. Confirmation of IPN position for GRB001204
  23. IPN triangulation of GRB001204 (short/hard)
  24. GRB 001105, further optical observations
  25. GRB001120: Gunn-i observations
  26. GRB001120: Optical observations
  27. GRB001109, optical observations
  28. GRB001120, optical observations
  29. IPN triangulation of GRB001120
  30. Optical/NIR observations of GRB001109
  31. GRB 001109: deep JHK upper limits
  32. GRB 001109 X-ray afterglow with BeppoSAX
  33. GRB001109: Optical observations
  34. GRB001109: BeppoSAX/NFI Observations
  35. GRB001109, R-band optical observations
  36. GRB001109, Radio observations
  37. BeppoSAX ALERT: GRB001109
  38. GRB001105 BVRI field photometry correction
  39. GRB001105, BVRI field photometry
  40. GRB 001105, R-band observation
  41. IPN TRIANGULATION OF GRB001105
  42. GRB 001025B, Optical obervations
  43. GRB 991208: HST Imaging of the Host Galaxy
  44. GRB000926: R-image of the host galaxy
  45. GRB 001025B, I-band observations
  46. GRB 001025 Optical Observations
  47. GRB 001025A, optical observation
  48. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  49. IPN triangulation of GRB001025
  50. ASM Localization of GRB 001025
  51. GRB001007, Radio observations
  52. IPN TRIANGULATION OF GRB001020
  53. GRB001019, Optical Observations
  54. GRB 001018, Possible Radio Afterglow
  55. GRB001018, Gamma Ray Observations
  56. IPN TRIANGULATION OF GRB001019
  57. IPN TRIANGULATION OF GRB001018
  58. IPN TRIANGULATION OF GRB 001017
  59. GRB 000926: Improved Absorber Redshift
  60. V,R,I band observations of GRB000926
  61. The Likely Optical/Infrared Afterglow of GRB 001011
  62. HETE positions added to GCN
  63. BeppoSAX ALERT: GRB001011
  64. GRB 001007, BVR-band observations
  65. GRB000926 - Amateur Optical Observations
  66. CONCAM null result on GRB001005
  67. IPN triangulation of GRB001007
  68. GRB 000926 : the host galaxy
  69. IPN triangulation of GRB001005
  70. GRB 000926 Chandra Observation
  71. IPN triangulation of GRB 001004
  72. Public availability of BeppoSAX data of GRB000926
  73. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  74. GRB 000926, Optical Decay
  75. GRB000926 - Optical observations
  76. GRB000926 - Optical observations
  77. GRB 000926: optical observations
  78. GRB 000926, Optical Observations
  79. GRB000926 K'-band Observation
  80. GRB000926 : increasing optical decay slope
  81. GRB000926 optical observations
  82. GRB000926 - Optical observations
  83. Re: GRB 000926, optical observation by Oksanen (vsnet-grb)
  84. J and K band observations of GRB 000926
  85. GRB 000926: Lightcurve Update and Predictions
  86. GRB 000926, optical observation by Oksanen (vsnet-grb)
  87. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  88. CONCAM crude optical limits before and after GRB000926
  89. GRB 000926: Preliminary R-band Lightcurve
  90. GRB 000926 HST/Chandra TOO Status
  91. Spectroscopic Redshift of GRB 000926
  92. GRB 000926, Optical Observation
  93. GRB 000926: Optical candidate
  94. Optical candidate for GRB000926
  95. IPN triangulation of GRB000926
  96. GRB 000911, BVRI field photometry
  97. GRB000911: Sub-millimeter observations
  98. IPN triangulation of GRB000925
  99. IPN triangulation of GRB000911
  100. IPN triangulation of GRB000910

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