Skip to main content
New! BOOM Notices and Schema v7.0.0. See news and announcements

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"

36352 results found.

  1. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  2. Optical observations of GRB 001018 with JCAM
  3. IPN TRIANGULATION OF GRB010115
  4. IPN TRIANGULATION OF GRB010109
  5. GRB010103, optical observations
  6. IPN triangulation of GRB010104
  7. IPN triangulation of GRB010103
  8. GRB 001204: Ks observations
  9. H band observation of GRB 001212
  10. GRB & BeppoSAX: ground operations restored back to 24 hrs a day
  11. IPN triangulation of GRB001219
  12. GRB 001212 Optical Observation
  13. GRB 001212 Optical Observation
  14. GRB 001212 optical observation
  15. GRB 001212 possible OA in 2MASS
  16. GRB 001212 possible OA
  17. IPN triangulation of GRB001212
  18. Confirmation of IPN position for GRB001204
  19. IPN triangulation of GRB001204 (short/hard)
  20. GRB 001105, further optical observations
  21. GRB001120: Gunn-i observations
  22. GRB001120: Optical observations
  23. GRB001109, optical observations
  24. GRB001120, optical observations
  25. WSRT 4.8 GHz observations of GRB001109
  26. IPN triangulation of GRB001120
  27. Optical/NIR observations of GRB001109
  28. GRB 001109: deep JHK upper limits
  29. GRB 001109 X-ray afterglow with BeppoSAX
  30. GRB001109: Optical observations
  31. GRB001109: BeppoSAX/NFI Observations
  32. GRB001109, R-band optical observations
  33. GRB001109, Radio observations
  34. BeppoSAX ALERT: GRB001109
  35. GRB001105 BVRI field photometry correction
  36. GRB001105, BVRI field photometry
  37. GRB 001105, R-band observation
  38. IPN TRIANGULATION OF GRB001105
  39. GRB 001025B, Optical obervations
  40. GRB 991208: HST Imaging of the Host Galaxy
  41. GRB000926: R-image of the host galaxy
  42. GRB 001025B, I-band observations
  43. GRB 001025 Optical Observations
  44. GRB 001025A, optical observation
  45. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  46. IPN triangulation of GRB001025
  47. ASM Localization of GRB 001025
  48. GRB001007, Radio observations
  49. IPN TRIANGULATION OF GRB001020
  50. GRB001019, Optical Observations
  51. GRB 001018, Possible Radio Afterglow
  52. GRB001018, Gamma Ray Observations
  53. IPN TRIANGULATION OF GRB001019
  54. IPN TRIANGULATION OF GRB001018
  55. IPN TRIANGULATION OF GRB 001017
  56. GRB 000926: Improved Absorber Redshift
  57. V,R,I band observations of GRB000926
  58. The Likely Optical/Infrared Afterglow of GRB 001011
  59. HETE positions added to GCN
  60. BeppoSAX ALERT: GRB001011
  61. GRB 001007, BVR-band observations
  62. GRB000926 - Amateur Optical Observations
  63. CONCAM null result on GRB001005
  64. IPN triangulation of GRB001007
  65. GRB 000926 : the host galaxy
  66. HETE-2 Launches Successfully
  67. IPN triangulation of GRB001005
  68. GRB 000926 Chandra Observation
  69. IPN triangulation of GRB 001004
  70. Public availability of BeppoSAX data of GRB000926
  71. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  72. GRB 000926, Optical Decay
  73. GRB000926 - Optical observations
  74. GRB000926 - Optical observations
  75. GRB 000926: optical observations
  76. GRB 000926, Optical Observations
  77. GRB000926 K'-band Observation
  78. GRB000926 : increasing optical decay slope
  79. GRB000926 optical observations
  80. GRB000926 - Optical observations
  81. Re: GRB 000926, optical observation by Oksanen (vsnet-grb)
  82. J and K band observations of GRB 000926
  83. GRB 000926: Lightcurve Update and Predictions
  84. GRB 000926, optical observation by Oksanen (vsnet-grb)
  85. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  86. CONCAM crude optical limits before and after GRB000926
  87. GRB 000926: Preliminary R-band Lightcurve
  88. GRB 000926 HST/Chandra TOO Status
  89. Spectroscopic Redshift of GRB 000926
  90. GRB 000926, Optical Observation
  91. GRB 000926: Optical candidate
  92. Optical candidate for GRB000926
  93. IPN triangulation of GRB000926
  94. GRB 000911, BVRI field photometry
  95. GRB000911: Sub-millimeter observations
  96. IPN triangulation of GRB000925
  97. IPN triangulation of GRB000911
  98. IPN triangulation of GRB000910
  99. False GRB alarm from RXTE/ASM on 8 Sept 2000
  100. GRB 000830: Optical observations

Advanced

Download all Circulars as a .tar.gz archive:
Questions or comments?
Contact GCN directly.
Have you found a bug in GCN?
Open an issue.
Want to contribute code to GCN?
Get involved on GitHub.

gcn.nasa.gov

A service of the Astrophysics Science Division at NASA Goddard Space Flight Center

Looking for U.S. government information and services? Visit USA.gov