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"

44417 results found.

  1. GRB010126 opt. obs.
  2. IPN/RXTE TRIANGULATION OF GRB010126
  3. GRB010126: CONCAM crude optical limits during GRB
  4. GRB010126, TNG R-band observations
  5. GRB010126 Optical Observations
  6. GRB010126 optical observations
  7. GRB010126: Optical observations
  8. IPN TRIANGULATION OF GRB010126
  9. IPN/RXTE TRIANGULATION OF GRB010126
  10. GRB 010119, optical observations
  11. GRB010119: Optical observations
  12. Optical Observations of GRB 001018 at Keck
  13. GRB010119, Radio observations
  14. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  15. Optical observations of GRB 001018 with JCAM
  16. IPN TRIANGULATION OF GRB010115
  17. IPN TRIANGULATION OF GRB010109
  18. IPN TRIANGULATION OF GRB010109
  19. GRB010103, optical observations
  20. IPN triangulation of GRB010104
  21. IPN triangulation of GRB010103
  22. GRB 001204: Ks observations
  23. H band observation of GRB 001212
  24. GRB & BeppoSAX: ground operations restored back to 24 hrs a day
  25. IPN triangulation of GRB001219
  26. GRB 001212 Optical Observation
  27. GRB 001212 Optical Observation
  28. GRB 001212 optical observation
  29. GRB 001212 possible OA in 2MASS
  30. GRB 001212 possible OA
  31. IPN triangulation of GRB001212
  32. GRB001204: Optical observations
  33. Confirmation of IPN position for GRB001204
  34. GRB001204, Radio observations
  35. IPN triangulation of GRB001204 (short/hard)
  36. GRB 001105, further optical observations
  37. GRB001120: Gunn-i observations
  38. GRB001120: Optical observations
  39. GRB001109, optical observations
  40. GRB001120, optical observations
  41. WSRT 4.8 GHz observations of GRB001109
  42. IPN triangulation of GRB001120
  43. Optical/NIR observations of GRB001109
  44. GRB 001109: deep JHK upper limits
  45. GRB 001109 X-ray afterglow with BeppoSAX
  46. CORRECTION to XMM-Newton observation of GRB001025
  47. GRB001109: Optical observations
  48. GRB001109: BeppoSAX/NFI Observations
  49. GRB001109, R-band optical observations
  50. GRB001109, Radio observations
  51. GRB001109: BeppoSAX refined WFC position
  52. BeppoSAX ALERT: GRB001109
  53. GRB001105, BVRI field photometry
  54. GRB 001105, R-band observation
  55. IPN TRIANGULATION OF GRB001105
  56. GRB 001025B, Optical obervations
  57. GRB 991208: HST Imaging of the Host Galaxy
  58. GRB000926: R-image of the host galaxy
  59. GRB 001025B, I-band observations
  60. XMM-Newton observation of GRB001025
  61. GRB001025B, Radio observations
  62. GRB 001025 Optical Observations
  63. GRB 001025A, optical observation
  64. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  65. CORRECTION TO IPN/RXTE ERROR BOX FOR GRB001025
  66. IPN triangulation of GRB001025
  67. GRB001007: Optical observations
  68. ASM Localization of GRB 001025
  69. GRB001007, Radio observations
  70. IPN TRIANGULATION OF GRB001020
  71. GRB001019, Optical Observations
  72. GRB 001018, Possible Radio Afterglow
  73. GRB001018, Gamma Ray Observations
  74. IPN TRIANGULATION OF GRB001019
  75. CORRECTION TO PEAK FLUX OF GRB001018
  76. IPN TRIANGULATION OF GRB001018
  77. IPN TRIANGULATION OF GRB 001017
  78. GRB 000926: Improved Absorber Redshift
  79. V,R,I band observations of GRB000926
  80. The Likely Optical/Infrared Afterglow of GRB 001011
  81. HETE positions added to GCN
  82. GRB001011 BeppoSAX/WFC refined position
  83. BeppoSAX ALERT: GRB001011
  84. GRB 001007, BVR-band observations
  85. GRB000926 - Amateur Optical Observations
  86. GRB001007: Optical observations
  87. CONCAM null result on GRB001005
  88. IPN triangulation of GRB001007
  89. GRB 000926 : the host galaxy
  90. HETE-2 Launches Successfully
  91. IPN triangulation of GRB001005
  92. HETE-2 48 hour Launch Delay
  93. GRB 000926 Chandra Observation
  94. IPN triangulation of GRB 001004
  95. Public availability of BeppoSAX data of GRB000926
  96. GRB000926: X-ray afterglow by BeppoSAX: revised fluxes (fwd)
  97. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  98. GRB000926 - Optical observations
  99. GRB000926 - Optical observations
  100. GRB 000926, Optical Decay

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