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"

37518 results found.

  1. GRB 001204: Ks observations
  2. H band observation of GRB 001212
  3. GRB & BeppoSAX: ground operations restored back to 24 hrs a day
  4. IPN triangulation of GRB001219
  5. GRB 001212 Optical Observation
  6. GRB 001212 Optical Observation
  7. GRB 001212 optical observation
  8. GRB 001212 possible OA in 2MASS
  9. GRB 001212 possible OA
  10. IPN triangulation of GRB001212
  11. Confirmation of IPN position for GRB001204
  12. IPN triangulation of GRB001204 (short/hard)
  13. GRB 001105, further optical observations
  14. GRB001120: Gunn-i observations
  15. GRB001120: Optical observations
  16. GRB001109, optical observations
  17. GRB001120, optical observations
  18. IPN triangulation of GRB001120
  19. Optical/NIR observations of GRB001109
  20. GRB 001109: deep JHK upper limits
  21. GRB 001109 X-ray afterglow with BeppoSAX
  22. GRB001109: Optical observations
  23. GRB001109: BeppoSAX/NFI Observations
  24. GRB001109, R-band optical observations
  25. GRB001109, Radio observations
  26. BeppoSAX ALERT: GRB001109
  27. GRB001105 BVRI field photometry correction
  28. GRB001105, BVRI field photometry
  29. GRB 001105, R-band observation
  30. IPN TRIANGULATION OF GRB001105
  31. GRB 001025B, Optical obervations
  32. GRB 991208: HST Imaging of the Host Galaxy
  33. GRB000926: R-image of the host galaxy
  34. GRB 001025B, I-band observations
  35. GRB 001025 Optical Observations
  36. GRB 001025A, optical observation
  37. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  38. IPN triangulation of GRB001025
  39. ASM Localization of GRB 001025
  40. GRB001007, Radio observations
  41. IPN TRIANGULATION OF GRB001020
  42. GRB001019, Optical Observations
  43. GRB 001018, Possible Radio Afterglow
  44. GRB001018, Gamma Ray Observations
  45. IPN TRIANGULATION OF GRB001019
  46. IPN TRIANGULATION OF GRB001018
  47. IPN TRIANGULATION OF GRB 001017
  48. GRB 000926: Improved Absorber Redshift
  49. V,R,I band observations of GRB000926
  50. The Likely Optical/Infrared Afterglow of GRB 001011
  51. HETE positions added to GCN
  52. BeppoSAX ALERT: GRB001011
  53. GRB 001007, BVR-band observations
  54. GRB000926 - Amateur Optical Observations
  55. CONCAM null result on GRB001005
  56. IPN triangulation of GRB001007
  57. GRB 000926 : the host galaxy
  58. IPN triangulation of GRB001005
  59. GRB 000926 Chandra Observation
  60. IPN triangulation of GRB 001004
  61. Public availability of BeppoSAX data of GRB000926
  62. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  63. GRB 000926, Optical Decay
  64. GRB000926 - Optical observations
  65. GRB000926 - Optical observations
  66. GRB 000926: optical observations
  67. GRB 000926, Optical Observations
  68. GRB000926 K'-band Observation
  69. GRB000926 : increasing optical decay slope
  70. GRB000926 optical observations
  71. GRB000926 - Optical observations
  72. Re: GRB 000926, optical observation by Oksanen (vsnet-grb)
  73. J and K band observations of GRB 000926
  74. GRB 000926: Lightcurve Update and Predictions
  75. GRB 000926, optical observation by Oksanen (vsnet-grb)
  76. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  77. CONCAM crude optical limits before and after GRB000926
  78. GRB 000926: Preliminary R-band Lightcurve
  79. GRB 000926 HST/Chandra TOO Status
  80. Spectroscopic Redshift of GRB 000926
  81. GRB 000926, Optical Observation
  82. GRB 000926: Optical candidate
  83. Optical candidate for GRB000926
  84. IPN triangulation of GRB000926
  85. GRB 000911, BVRI field photometry
  86. GRB000911: Sub-millimeter observations
  87. IPN triangulation of GRB000925
  88. IPN triangulation of GRB000911
  89. IPN triangulation of GRB000910
  90. False GRB alarm from RXTE/ASM on 8 Sept 2000
  91. GRB 000830: Optical observations
  92. GRB000830: Optical observations
  93. GRB000830, TNG B-band observations
  94. GRB000830, BVRI field photometry
  95. GRB000830: Optical observations
  96. GRB000210, Optical observations
  97. Chandra Position of GRB000210
  98. "Snapshot" afterglow IDs and GRB 000830
  99. IPN triangulation of GRB000830
  100. HST/STIS observations of the host galaxy of GRB 980329

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