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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"

23601 results found.

  1. IPN triangulation of GRB010104
  2. IPN triangulation of GRB010103
  3. H band observation of GRB 001212
  4. IPN triangulation of GRB001219
  5. GRB 001212 Optical Observation
  6. GRB 001212 Optical Observation
  7. GRB 001212 optical observation
  8. GRB 001212 possible OA in 2MASS
  9. GRB 001212 possible OA
  10. IPN triangulation of GRB001212
  11. GRB001204, Radio observations
  12. IPN triangulation of GRB001204 (short/hard)
  13. GRB 001105, further optical observations
  14. GRB001120: Gunn-i observations
  15. GRB001120, optical observations
  16. IPN triangulation of GRB001120
  17. Optical/NIR observations of GRB001109
  18. GRB 001109: deep JHK upper limits
  19. GRB 001109 X-ray afterglow with BeppoSAX
  20. GRB001109: Optical observations
  21. GRB001105, BVRI field photometry
  22. GRB 001105, R-band observation
  23. IPN TRIANGULATION OF GRB001105
  24. GRB 001025B, Optical obervations
  25. GRB000926: R-image of the host galaxy
  26. GRB 001025B, I-band observations
  27. XMM-Newton observation of GRB001025
  28. GRB001025B, Radio observations
  29. GRB 001025 Optical Observations
  30. GRB 001025A, optical observation
  31. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  32. CORRECTION TO IPN/RXTE ERROR BOX FOR GRB001025
  33. IPN triangulation of GRB001025
  34. ASM Localization of GRB 001025
  35. IPN TRIANGULATION OF GRB001020
  36. IPN TRIANGULATION OF GRB001019
  37. CORRECTION TO PEAK FLUX OF GRB001018
  38. IPN TRIANGULATION OF GRB001018
  39. IPN TRIANGULATION OF GRB 001017
  40. GRB 000926: Improved Absorber Redshift
  41. V,R,I band observations of GRB000926
  42. The Likely Optical/Infrared Afterglow of GRB 001011
  43. IPN triangulation of GRB001007
  44. GRB 000926 : the host galaxy
  45. IPN triangulation of GRB001005
  46. HETE-2 48 hour Launch Delay
  47. GRB 000926 Chandra Observation
  48. IPN triangulation of GRB 001004
  49. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  50. GRB000926 - Optical observations
  51. GRB000926 - Optical observations
  52. GRB000926 - Optical observations
  53. GRB000926 - Optical observations
  54. GRB000926 - Optical observations
  55. GRB000926 K'-band Observation
  56. GRB000926 optical observations
  57. GRB000926 - Optical observations
  58. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  59. CONCAM crude optical limits before and after GRB000926
  60. GRB 000926: Preliminary R-band Lightcurve
  61. IPN triangulation of GRB000926
  62. IPN triangulation of GRB000926
  63. GRB 000911, BVRI field photometry
  64. IPN triangulation of GRB000925
  65. IPN triangulation of GRB000911
  66. IPN triangulation of GRB000910
  67. False GRB alarm from RXTE/ASM on 8 Sept 2000
  68. GRB 000830: Optical observations
  69. GRB000830, TNG B-band observations
  70. GRB000830, BVRI field photometry
  71. GRB000210, Optical observations
  72. IPN triangulation of GRB000830
  73. IPN localization of GRB000820
  74. GRB000812, TNG R-band observations
  75. GRB000730, Gamma Ray Observations
  76. GRB000812, Radio observations
  77. IPN localization of GRB000812
  78. IPN localization of GRB000811
  79. GRB000801, Gamma Ray Observations
  80. GRB000801, Radio Observations
  81. GRB 991208 Host Galaxy Imaging
  82. Updated IPN coordinates for GRB000801
  83. IPN localization of GRB000801
  84. IPN localization of GRB000730B
  85. IPN localization of GRB000730B
  86. IPN localization of GRB000730
  87. GRB 000727, optical observations
  88. IPN localization of GRB000727
  89. GRB 990705, HST/STIS observations of the host galaxy
  90. GRB 991216, HST/STIS observations
  91. GRB 000630: Detection of the Optical Afterglow
  92. GRB000630, Revised BVRI Field Photometry
  93. GRB000630, optical observations
  94. GRB000630, BVRI Field Photometry
  95. GRB000630, optical observations
  96. GRB000630, optical observations
  97. GRB000630: Optical observations
  98. IPN triangulation of GRB000630
  99. GRB 000623, optical observations
  100. GRB 000620, optical observations

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