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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"

41684 results found.

  1. CORRECTION to XMM-Newton observation of GRB001025
  2. GRB001109: Optical observations
  3. GRB001109: BeppoSAX/NFI Observations
  4. GRB001109, R-band optical observations
  5. GRB001109, Radio observations
  6. GRB001105 BVRI field photometry correction
  7. GRB001105, BVRI field photometry
  8. GRB 001105, R-band observation
  9. GRB 001025B, Optical obervations
  10. GRB 991208: HST Imaging of the Host Galaxy
  11. GRB000926: R-image of the host galaxy
  12. GRB 001025B, I-band observations
  13. XMM-Newton observation of GRB001025
  14. GRB001025B, Radio observations
  15. GRB 001025 Optical Observations
  16. GRB 001025A, optical observation
  17. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  18. CORRECTION TO IPN/RXTE ERROR BOX FOR GRB001025
  19. IPN triangulation of GRB001025
  20. GRB001007: Optical observations
  21. ASM Localization of GRB 001025
  22. GRB001007, Radio observations
  23. GRB001019, Optical Observations
  24. GRB 001018, Possible Radio Afterglow
  25. GRB001018, Gamma Ray Observations
  26. CORRECTION TO PEAK FLUX OF GRB001018
  27. GRB 000926: Improved Absorber Redshift
  28. V,R,I band observations of GRB000926
  29. The Likely Optical/Infrared Afterglow of GRB 001011
  30. HETE positions added to GCN
  31. GRB001011 BeppoSAX/WFC refined position
  32. GRB 001007, BVR-band observations
  33. GRB000926 - Amateur Optical Observations
  34. GRB001007: Optical observations
  35. CONCAM null result on GRB001005
  36. GRB 000926 : the host galaxy
  37. HETE-2 Launches Successfully
  38. GRB 000926 Chandra Observation
  39. Public availability of BeppoSAX data of GRB000926
  40. GRB000926: X-ray afterglow by BeppoSAX: revised fluxes (fwd)
  41. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  42. GRB000926 - Optical observations
  43. GRB000926 - Optical observations
  44. GRB 000926, Optical Decay
  45. GRB000911: VLT infrared observation
  46. GRB000926 - Optical observations
  47. GRB000926 - Optical observations
  48. GRB 000926: optical observations
  49. GRB 000926, Optical Observations
  50. GRB000926 - Optical observations
  51. GRB000911: optical VLT observations
  52. GRB000926 K'-band Observation
  53. GRB000926 : increasing optical decay slope
  54. GRB000926 optical observations
  55. GRB000926 - Optical observations
  56. Re: GRB 000926, optical observation by Oksanen (vsnet-grb)
  57. J and K band observations of GRB 000926
  58. GRB000911 Optical Observations
  59. GRB 000926: Lightcurve Update and Predictions
  60. GRB 000926, optical observation by Oksanen (vsnet-grb)
  61. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  62. GRB000926: Optical observations
  63. CONCAM crude optical limits before and after GRB000926
  64. GRB 000926: Preliminary R-band Lightcurve
  65. GRB 000926 HST/Chandra TOO Status
  66. Spectroscopic Redshift of GRB 000926
  67. GRB 000926, Optical Observation
  68. GRB000926, radio observations
  69. GRB 000926: Optical candidate
  70. Optical candidate for GRB000926
  71. IPN triangulation of GRB000926
  72. GRB 000911, BVRI field photometry
  73. GRB000911: Corrected coordinates
  74. GRB000911: Sub-millimeter observations
  75. GRB000911: Optical Transient
  76. GRB000911, Radio and Optical observations
  77. GRB000911, Radio observations
  78. GRB000911: Optical observations
  79. False GRB alarm from RXTE/ASM on 8 Sept 2000
  80. GRB 000830: Optical observations
  81. GRB000830: Optical observations
  82. GRB000830, TNG B-band observations
  83. GRB000830, BVRI field photometry
  84. GRB000830: Optical observations
  85. GRB000210, Optical observations
  86. Chandra Position of GRB000210
  87. "Snapshot" afterglow IDs and GRB 000830
  88. GRB000830: Optical observations
  89. HST/STIS observations of the host galaxy of GRB 980329
  90. HST/STIS observations of the chaotic environment of GRB 980613
  91. GRB000812, TNG R-band observations
  92. GRB000801 & GRB000730, Gamma Ray Observations
  93. GRB000730, Gamma Ray Observations
  94. GRB000812, Radio observations
  95. GRB000801, Gamma Ray Observations
  96. GRB000801, VLT-Antu R-band observations
  97. GRB000301C, UBVI optical observations
  98. GRB000801, Radio Observations
  99. GRB 991208 Host Galaxy Imaging
  100. Updated IPN coordinates for GRB000801

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