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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"

35434 results found.

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

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