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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"

35428 results found.

  1. Optical observations of GRB 001018 with JCAM
  2. IPN TRIANGULATION OF GRB010115
  3. IPN TRIANGULATION OF GRB010109
  4. GRB010103, optical observations
  5. IPN triangulation of GRB010104
  6. IPN triangulation of GRB010103
  7. GRB 001204: Ks observations
  8. H band observation of GRB 001212
  9. GRB & BeppoSAX: ground operations restored back to 24 hrs a day
  10. IPN triangulation of GRB001219
  11. GRB 001212 Optical Observation
  12. GRB 001212 Optical Observation
  13. GRB 001212 optical observation
  14. GRB 001212 possible OA in 2MASS
  15. GRB 001212 possible OA
  16. IPN triangulation of GRB001212
  17. Confirmation of IPN position for GRB001204
  18. IPN triangulation of GRB001204 (short/hard)
  19. GRB 001105, further optical observations
  20. GRB001120: Gunn-i observations
  21. GRB001120: Optical observations
  22. GRB001109, optical observations
  23. GRB001120, optical observations
  24. IPN triangulation of GRB001120
  25. Optical/NIR observations of GRB001109
  26. GRB 001109: deep JHK upper limits
  27. GRB 001109 X-ray afterglow with BeppoSAX
  28. GRB001109: Optical observations
  29. GRB001109: BeppoSAX/NFI Observations
  30. GRB001109, R-band optical observations
  31. GRB001109, Radio observations
  32. BeppoSAX ALERT: GRB001109
  33. GRB001105 BVRI field photometry correction
  34. GRB001105, BVRI field photometry
  35. GRB 001105, R-band observation
  36. IPN TRIANGULATION OF GRB001105
  37. GRB 001025B, Optical obervations
  38. GRB 991208: HST Imaging of the Host Galaxy
  39. GRB000926: R-image of the host galaxy
  40. GRB 001025B, I-band observations
  41. GRB 001025 Optical Observations
  42. GRB 001025A, optical observation
  43. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  44. IPN triangulation of GRB001025
  45. ASM Localization of GRB 001025
  46. GRB001007, Radio observations
  47. IPN TRIANGULATION OF GRB001020
  48. GRB001019, Optical Observations
  49. GRB 001018, Possible Radio Afterglow
  50. GRB001018, Gamma Ray Observations
  51. IPN TRIANGULATION OF GRB001019
  52. IPN TRIANGULATION OF GRB001018
  53. IPN TRIANGULATION OF GRB 001017
  54. GRB 000926: Improved Absorber Redshift
  55. V,R,I band observations of GRB000926
  56. The Likely Optical/Infrared Afterglow of GRB 001011
  57. HETE positions added to GCN
  58. BeppoSAX ALERT: GRB001011
  59. GRB 001007, BVR-band observations
  60. GRB000926 - Amateur Optical Observations
  61. CONCAM null result on GRB001005
  62. IPN triangulation of GRB001007
  63. GRB 000926 : the host galaxy
  64. IPN triangulation of GRB001005
  65. GRB 000926 Chandra Observation
  66. IPN triangulation of GRB 001004
  67. Public availability of BeppoSAX data of GRB000926
  68. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  69. GRB 000926, Optical Decay
  70. GRB000926 - Optical observations
  71. GRB000926 - Optical observations
  72. GRB 000926: optical observations
  73. GRB 000926, Optical Observations
  74. GRB000926 K'-band Observation
  75. GRB000926 : increasing optical decay slope
  76. GRB000926 optical observations
  77. GRB000926 - Optical observations
  78. Re: GRB 000926, optical observation by Oksanen (vsnet-grb)
  79. J and K band observations of GRB 000926
  80. GRB 000926: Lightcurve Update and Predictions
  81. GRB 000926, optical observation by Oksanen (vsnet-grb)
  82. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  83. CONCAM crude optical limits before and after GRB000926
  84. GRB 000926: Preliminary R-band Lightcurve
  85. GRB 000926 HST/Chandra TOO Status
  86. Spectroscopic Redshift of GRB 000926
  87. GRB 000926, Optical Observation
  88. GRB 000926: Optical candidate
  89. Optical candidate for GRB000926
  90. IPN triangulation of GRB000926
  91. GRB 000911, BVRI field photometry
  92. GRB000911: Sub-millimeter observations
  93. IPN triangulation of GRB000925
  94. IPN triangulation of GRB000911
  95. IPN triangulation of GRB000910
  96. False GRB alarm from RXTE/ASM on 8 Sept 2000
  97. GRB 000830: Optical observations
  98. GRB000830: Optical observations
  99. GRB000830, TNG B-band observations
  100. GRB000830, BVRI field photometry

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