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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"

37500 results found.

  1. Optical/NIR observations of GRB001109
  2. GRB 001109: deep JHK upper limits
  3. GRB 001109 X-ray afterglow with BeppoSAX
  4. GRB001109: Optical observations
  5. GRB001109: BeppoSAX/NFI Observations
  6. GRB001109, R-band optical observations
  7. GRB001109, Radio observations
  8. BeppoSAX ALERT: GRB001109
  9. GRB001105 BVRI field photometry correction
  10. GRB001105, BVRI field photometry
  11. GRB 001105, R-band observation
  12. IPN TRIANGULATION OF GRB001105
  13. GRB 001025B, Optical obervations
  14. GRB 991208: HST Imaging of the Host Galaxy
  15. GRB000926: R-image of the host galaxy
  16. GRB 001025B, I-band observations
  17. GRB 001025 Optical Observations
  18. GRB 001025A, optical observation
  19. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  20. IPN triangulation of GRB001025
  21. ASM Localization of GRB 001025
  22. GRB001007, Radio observations
  23. IPN TRIANGULATION OF GRB001020
  24. GRB001019, Optical Observations
  25. GRB 001018, Possible Radio Afterglow
  26. GRB001018, Gamma Ray Observations
  27. IPN TRIANGULATION OF GRB001019
  28. IPN TRIANGULATION OF GRB001018
  29. IPN TRIANGULATION OF GRB 001017
  30. GRB 000926: Improved Absorber Redshift
  31. V,R,I band observations of GRB000926
  32. The Likely Optical/Infrared Afterglow of GRB 001011
  33. HETE positions added to GCN
  34. BeppoSAX ALERT: GRB001011
  35. GRB 001007, BVR-band observations
  36. GRB000926 - Amateur Optical Observations
  37. CONCAM null result on GRB001005
  38. IPN triangulation of GRB001007
  39. GRB 000926 : the host galaxy
  40. IPN triangulation of GRB001005
  41. GRB 000926 Chandra Observation
  42. IPN triangulation of GRB 001004
  43. Public availability of BeppoSAX data of GRB000926
  44. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  45. GRB 000926, Optical Decay
  46. GRB000926 - Optical observations
  47. GRB000926 - Optical observations
  48. GRB 000926: optical observations
  49. GRB 000926, Optical Observations
  50. GRB000926 K'-band Observation
  51. GRB000926 : increasing optical decay slope
  52. GRB000926 optical observations
  53. GRB000926 - Optical observations
  54. Re: GRB 000926, optical observation by Oksanen (vsnet-grb)
  55. J and K band observations of GRB 000926
  56. GRB 000926: Lightcurve Update and Predictions
  57. GRB 000926, optical observation by Oksanen (vsnet-grb)
  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. GRB 000926 HST/Chandra TOO Status
  62. Spectroscopic Redshift of GRB 000926
  63. GRB 000926, Optical Observation
  64. GRB 000926: Optical candidate
  65. Optical candidate for GRB000926
  66. IPN triangulation of GRB000926
  67. GRB 000911, BVRI field photometry
  68. GRB000911: Sub-millimeter observations
  69. IPN triangulation of GRB000925
  70. IPN triangulation of GRB000911
  71. IPN triangulation of GRB000910
  72. False GRB alarm from RXTE/ASM on 8 Sept 2000
  73. GRB 000830: Optical observations
  74. GRB000830: Optical observations
  75. GRB000830, TNG B-band observations
  76. GRB000830, BVRI field photometry
  77. GRB000830: Optical observations
  78. GRB000210, Optical observations
  79. Chandra Position of GRB000210
  80. "Snapshot" afterglow IDs and GRB 000830
  81. IPN triangulation of GRB000830
  82. HST/STIS observations of the host galaxy of GRB 980329
  83. HST/STIS observations of the chaotic environment of GRB 980613
  84. IPN localization of GRB000820
  85. GRB000801 & GRB000730, Gamma Ray Observations
  86. GRB000730, Gamma Ray Observations
  87. GRB000812, Radio observations
  88. IPN localization of GRB000812
  89. IPN localization of GRB000811
  90. GRB000801, Gamma Ray Observations
  91. GRB000801, VLT-Antu R-band observations
  92. GRB 991208 Host Galaxy Imaging
  93. Updated IPN coordinates for GRB000801
  94. IPN localization of GRB000801
  95. IPN localization of GRB000730B
  96. IPN localization of GRB000730B
  97. IPN localization of GRB000730
  98. GRB 990510: Possible detection of a host galaxy
  99. GRB 990510 Host Galaxy Discovery
  100. GRB 000727, optical observations

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