Skip to main content
Updates to LVK & CHIME Notices, Schema v7.2.3! 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"

35946 results found.

  1. GRB 010214 optical observation
  2. GRB010213 Optical Observation
  3. J-Band Observation of GRB 010214.
  4. GRB010213, Near-IR observations
  5. Possible InfraRed Transient of GRB 010214.
  6. GRB010214 Optical Observation
  7. GRB010214: BeppoSAX/NFI Observations
  8. GRB010213 (HETE) TAROT observations
  9. GRB 010214, optical observations
  10. BeppoSAX ALERT: GRB010214
  11. IPN Status Report
  12. HETE Status
  13. GRB010126 opt. obs.
  14. IPN/RXTE TRIANGULATION OF GRB010126
  15. GRB010126: CONCAM crude optical limits during GRB
  16. GRB010126, TNG R-band observations
  17. IPN TRIANGULATION OF GRB010126
  18. IPN/RXTE TRIANGULATION OF GRB010126
  19. GRB 010119, optical observations
  20. GRB010119: Optical observations
  21. Optical Observations of GRB 001018 at Keck
  22. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  23. Optical observations of GRB 001018 with JCAM
  24. IPN TRIANGULATION OF GRB010115
  25. IPN TRIANGULATION OF GRB010109
  26. GRB010103, optical observations
  27. IPN triangulation of GRB010104
  28. IPN triangulation of GRB010103
  29. GRB 001204: Ks observations
  30. H band observation of GRB 001212
  31. GRB & BeppoSAX: ground operations restored back to 24 hrs a day
  32. IPN triangulation of GRB001219
  33. GRB 001212 Optical Observation
  34. GRB 001212 Optical Observation
  35. GRB 001212 optical observation
  36. GRB 001212 possible OA in 2MASS
  37. GRB 001212 possible OA
  38. IPN triangulation of GRB001212
  39. Confirmation of IPN position for GRB001204
  40. IPN triangulation of GRB001204 (short/hard)
  41. GRB 001105, further optical observations
  42. GRB001120: Gunn-i observations
  43. GRB001120: Optical observations
  44. GRB001109, optical observations
  45. GRB001120, optical observations
  46. IPN triangulation of GRB001120
  47. Optical/NIR observations of GRB001109
  48. GRB 001109: deep JHK upper limits
  49. GRB 001109 X-ray afterglow with BeppoSAX
  50. GRB001109: Optical observations
  51. GRB001109: BeppoSAX/NFI Observations
  52. GRB001109, R-band optical observations
  53. GRB001109, Radio observations
  54. BeppoSAX ALERT: GRB001109
  55. GRB001105 BVRI field photometry correction
  56. GRB001105, BVRI field photometry
  57. GRB 001105, R-band observation
  58. IPN TRIANGULATION OF GRB001105
  59. GRB 001025B, Optical obervations
  60. GRB 991208: HST Imaging of the Host Galaxy
  61. GRB000926: R-image of the host galaxy
  62. GRB 001025B, I-band observations
  63. GRB 001025 Optical Observations
  64. GRB 001025A, optical observation
  65. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  66. IPN triangulation of GRB001025
  67. ASM Localization of GRB 001025
  68. GRB001007, Radio observations
  69. IPN TRIANGULATION OF GRB001020
  70. GRB001019, Optical Observations
  71. GRB 001018, Possible Radio Afterglow
  72. GRB001018, Gamma Ray Observations
  73. IPN TRIANGULATION OF GRB001019
  74. IPN TRIANGULATION OF GRB001018
  75. IPN TRIANGULATION OF GRB 001017
  76. GRB 000926: Improved Absorber Redshift
  77. V,R,I band observations of GRB000926
  78. The Likely Optical/Infrared Afterglow of GRB 001011
  79. HETE positions added to GCN
  80. BeppoSAX ALERT: GRB001011
  81. GRB 001007, BVR-band observations
  82. GRB000926 - Amateur Optical Observations
  83. CONCAM null result on GRB001005
  84. IPN triangulation of GRB001007
  85. GRB 000926 : the host galaxy
  86. IPN triangulation of GRB001005
  87. GRB 000926 Chandra Observation
  88. IPN triangulation of GRB 001004
  89. Public availability of BeppoSAX data of GRB000926
  90. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  91. GRB 000926, Optical Decay
  92. GRB000926 - Optical observations
  93. GRB000926 - Optical observations
  94. GRB 000926: optical observations
  95. GRB 000926, Optical Observations
  96. GRB000926 K'-band Observation
  97. GRB000926 : increasing optical decay slope
  98. GRB000926 optical observations
  99. GRB000926 - Optical observations
  100. Re: GRB 000926, optical observation by Oksanen (vsnet-grb)

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
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