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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"

37514 results found.

  1. GRB 001212 Optical Observation
  2. GRB 001212 Optical Observation
  3. GRB 001212 optical observation
  4. GRB 001212 possible OA in 2MASS
  5. GRB 001212 possible OA
  6. IPN triangulation of GRB001212
  7. Confirmation of IPN position for GRB001204
  8. IPN triangulation of GRB001204 (short/hard)
  9. GRB 001105, further optical observations
  10. GRB001120: Gunn-i observations
  11. GRB001120: Optical observations
  12. GRB001109, optical observations
  13. GRB001120, optical observations
  14. IPN triangulation of GRB001120
  15. Optical/NIR observations of GRB001109
  16. GRB 001109: deep JHK upper limits
  17. GRB 001109 X-ray afterglow with BeppoSAX
  18. GRB001109: Optical observations
  19. GRB001109: BeppoSAX/NFI Observations
  20. GRB001109, R-band optical observations
  21. GRB001109, Radio observations
  22. BeppoSAX ALERT: GRB001109
  23. GRB001105 BVRI field photometry correction
  24. GRB001105, BVRI field photometry
  25. GRB 001105, R-band observation
  26. IPN TRIANGULATION OF GRB001105
  27. GRB 001025B, Optical obervations
  28. GRB 991208: HST Imaging of the Host Galaxy
  29. GRB000926: R-image of the host galaxy
  30. GRB 001025B, I-band observations
  31. GRB 001025 Optical Observations
  32. GRB 001025A, optical observation
  33. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  34. IPN triangulation of GRB001025
  35. ASM Localization of GRB 001025
  36. GRB001007, Radio observations
  37. IPN TRIANGULATION OF GRB001020
  38. GRB001019, Optical Observations
  39. GRB 001018, Possible Radio Afterglow
  40. GRB001018, Gamma Ray Observations
  41. IPN TRIANGULATION OF GRB001019
  42. IPN TRIANGULATION OF GRB001018
  43. IPN TRIANGULATION OF GRB 001017
  44. GRB 000926: Improved Absorber Redshift
  45. V,R,I band observations of GRB000926
  46. The Likely Optical/Infrared Afterglow of GRB 001011
  47. HETE positions added to GCN
  48. BeppoSAX ALERT: GRB001011
  49. GRB 001007, BVR-band observations
  50. GRB000926 - Amateur Optical Observations
  51. CONCAM null result on GRB001005
  52. IPN triangulation of GRB001007
  53. GRB 000926 : the host galaxy
  54. IPN triangulation of GRB001005
  55. GRB 000926 Chandra Observation
  56. IPN triangulation of GRB 001004
  57. Public availability of BeppoSAX data of GRB000926
  58. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  59. GRB 000926, Optical Decay
  60. GRB000926 - Optical observations
  61. GRB000926 - Optical observations
  62. GRB 000926: optical observations
  63. GRB 000926, Optical Observations
  64. GRB000926 K'-band Observation
  65. GRB000926 : increasing optical decay slope
  66. GRB000926 optical observations
  67. GRB000926 - Optical observations
  68. Re: GRB 000926, optical observation by Oksanen (vsnet-grb)
  69. J and K band observations of GRB 000926
  70. GRB 000926: Lightcurve Update and Predictions
  71. GRB 000926, optical observation by Oksanen (vsnet-grb)
  72. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  73. CONCAM crude optical limits before and after GRB000926
  74. GRB 000926: Preliminary R-band Lightcurve
  75. GRB 000926 HST/Chandra TOO Status
  76. Spectroscopic Redshift of GRB 000926
  77. GRB 000926, Optical Observation
  78. GRB 000926: Optical candidate
  79. Optical candidate for GRB000926
  80. IPN triangulation of GRB000926
  81. GRB 000911, BVRI field photometry
  82. GRB000911: Sub-millimeter observations
  83. IPN triangulation of GRB000925
  84. IPN triangulation of GRB000911
  85. IPN triangulation of GRB000910
  86. False GRB alarm from RXTE/ASM on 8 Sept 2000
  87. GRB 000830: Optical observations
  88. GRB000830: Optical observations
  89. GRB000830, TNG B-band observations
  90. GRB000830, BVRI field photometry
  91. GRB000830: Optical observations
  92. GRB000210, Optical observations
  93. Chandra Position of GRB000210
  94. "Snapshot" afterglow IDs and GRB 000830
  95. IPN triangulation of GRB000830
  96. HST/STIS observations of the host galaxy of GRB 980329
  97. HST/STIS observations of the chaotic environment of GRB 980613
  98. IPN localization of GRB000820
  99. GRB000801 & GRB000730, Gamma Ray Observations
  100. GRB000730, Gamma Ray Observations

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