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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"

31742 results found.

  1. GRB 001212 possible OA
  2. GRB001204: Optical observations
  3. Confirmation of IPN position for GRB001204
  4. GRB001204, Radio observations
  5. GRB 001105, further optical observations
  6. GRB001120: Gunn-i observations
  7. GRB001109, optical observations
  8. WSRT 4.8 GHz observations of GRB001109
  9. Optical/NIR observations of GRB001109
  10. GRB 001109: deep JHK upper limits
  11. GRB 001109 X-ray afterglow with BeppoSAX
  12. CORRECTION to XMM-Newton observation of GRB001025
  13. GRB001109: Optical observations
  14. GRB001109, R-band optical observations
  15. GRB001109, Radio observations
  16. GRB001105 BVRI field photometry correction
  17. GRB001105, BVRI field photometry
  18. GRB 001105, R-band observation
  19. GRB 991208: HST Imaging of the Host Galaxy
  20. GRB000926: R-image of the host galaxy
  21. GRB 001025B, I-band observations
  22. XMM-Newton observation of GRB001025
  23. GRB001025B, Radio observations
  24. GRB 001025 Optical Observations
  25. GRB 001025A, optical observation
  26. CORRECTION TO IPN/RXTE ERROR BOX FOR GRB001025
  27. IPN triangulation of GRB001025
  28. GRB001007: Optical observations
  29. GRB001007, Radio observations
  30. GRB 001018, Possible Radio Afterglow
  31. CORRECTION TO PEAK FLUX OF GRB001018
  32. GRB 000926: Improved Absorber Redshift
  33. V,R,I band observations of GRB000926
  34. The Likely Optical/Infrared Afterglow of GRB 001011
  35. HETE positions added to GCN
  36. GRB 001007, BVR-band observations
  37. GRB001007: Optical observations
  38. CONCAM null result on GRB001005
  39. GRB 000926 : the host galaxy
  40. GRB 000926 Chandra Observation
  41. Public availability of BeppoSAX data of GRB000926
  42. GRB000926: X-ray afterglow by BeppoSAX: revised fluxes (fwd)
  43. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  44. GRB000926 - Optical observations
  45. GRB000926 - Optical observations
  46. GRB 000926, Optical Decay
  47. GRB000911: VLT infrared observation
  48. GRB000926 - Optical observations
  49. GRB000926 - Optical observations
  50. GRB 000926: optical observations
  51. GRB 000926, Optical Observations
  52. GRB000926 - Optical observations
  53. GRB000911: optical VLT observations
  54. GRB000926 : increasing optical decay slope
  55. GRB000926 optical observations
  56. GRB000926 - Optical observations
  57. Re: GRB 000926, optical observation by Oksanen (vsnet-grb)
  58. J and K band observations of GRB 000926
  59. GRB000911 Optical Observations
  60. GRB 000926: Lightcurve Update and Predictions
  61. GRB 000926, optical observation by Oksanen (vsnet-grb)
  62. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  63. GRB000926: Optical observations
  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: Optical observations
  84. GRB000210, Optical observations
  85. Chandra Position of GRB000210
  86. GRB000830: Optical observations
  87. HST/STIS observations of the host galaxy of GRB 980329
  88. HST/STIS observations of the chaotic environment of GRB 980613
  89. GRB000812, TNG R-band observations
  90. GRB000801 & GRB000730, Gamma Ray Observations
  91. GRB000812, Radio observations
  92. GRB000801, VLT-Antu R-band observations
  93. GRB000301C, UBVI optical observations
  94. GRB000801, Radio Observations
  95. GRB 991208 Host Galaxy Imaging
  96. Updated IPN coordinates for GRB000801
  97. IPN localization of GRB000801
  98. IPN localization of GRB000730B
  99. GRB 990510: Possible detection of a host galaxy
  100. GRB 990510 Host Galaxy Discovery

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