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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"

35427 results found.

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

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