Skip to main content
Circulars over Kafka event name backfill. 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"

24598 results found.

  1. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  2. Optical Observations of GRB990627
  3. BeppoSAX: GRB990625
  4. Late-time HST/STIS Observation of GRB 990123
  5. Optical Observations of GRB 990506
  6. GRB990527 Optical Observations
  7. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  8. Late Afterglows of GRBs 990510, 990123
  9. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  10. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  11. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  12. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  13. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  14. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  15. radio observations of X-ray/GRB transient field
  16. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  17. Optical report on X-ray/GRB transient
  18. radio detection of X-ray/GRB transient
  19. BeppoSAX: A new fast X-ray transient
  20. GRB 990510: optical observations
  21. GRB 990510: optical linear polarization
  22. GRB 990510: optical observations
  23. GRB990510: X-ray afterglow
  24. GRB 990510: Broad Band Break
  25. GRB 990510: BATSE Observations
  26. GRB 990510: BeppoSAX/GRBM observations
  27. GRB990510 optical observations
  28. GRB 990510 optical observations
  29. GRB 990506 Radio Observations
  30. GRB 990123, optical monitoring
  31. GRB 990506: BATSE Observations
  32. GRB 990506, optical observations
  33. GRB 990506, Optical Observations
  34. GRB 990506 optical observations
  35. GRB 990506, optical observations
  36. GRB 990506, armchair astronomy
  37. GRB 990506, optical observations from +1 to +3 hours
  38. GRB 990506, optical observations
  39. GRB990506 observation plan
  40. IPN localization for GRB990506
  41. GRB990323 PRECISE IPN POSITION
  42. GRB 990316 Optical Observations
  43. GRB 990316 optical observations
  44. GRB990316: simultaneous optical observation
  45. GRB990316 - Optical null results
  46. GRB990308 not a new SGR
  47. GRB 990308a and GRB 990308b
  48. GRB990308, Possible new SGR~0209+70
  49. GRB 990123, Field Photometry
  50. GRB 990217 Optical Observations
  51. BATSE Flight Anomaly
  52. GRB990217: BeppoSAX/GRBM data
  53. GRB990123 observations
  54. GRB990217 Optical observation
  55. GRB990123, Optical Observation
  56. GRB 990123: Discovery of the Probable Host Galaxy
  57. GRB 990123: Reduced HST Images
  58. GRB19990123 observations
  59. GRB 990123: BVRI standards in the field
  60. GRB981220, field photometry
  61. GRB990123, Optical observation
  62. GRB990123, 15-GHz limits
  63. GRB 990123: New Constraints on Possible Foreground Galaxies
  64. GRB990123 Optical Observations
  65. GRB990123, Probability of gravitational lensing
  66. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  67. GRB990123, Preliminary Lens Search Results
  68. On the Lensing Interpretation of GRB 990123
  69. Search for Potential Images of GRB 990123
  70. Search for Potential Images of GRB 990123
  71. GRB990123, Optical BVRI Observations
  72. GRB 990123: near-infrared observations.
  73. GRB990123, OSSE observations
  74. GRB990123: NIR Observation
  75. GRB990123, ASCA X-ray observation of afterglow
  76. "GRB 990123: New BV Observations"
  77. GRB 990123 Optical Follow-Up
  78. GRB 990123: BATSE Observations
  79. GRB990123 Optical Observations
  80. GRB 990123: New Optical Observations, Decay Measure
  81. GRB 990123 Optical Follow-Up
  82. GRB 990123: Possible Gravitationally Lensed Burst?
  83. GRB990123, optical observation
  84. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  85. GRB990123, Optical observation
  86. GRB 990123: Optical Decay Slope
  87. GRB 990123 r-band photometry
  88. GRB 990123 Optical Follow-up
  89. GRB990123, early optical counterpart detection
  90. GRB990123 Optical Observation
  91. Possible identification of SN1999E with GRB980910
  92. Optical Observations of GRB 981220
  93. GRB 981226: radio variable
  94. GRB981220
  95. GRB981220, Correction to GCN 179
  96. GRB 981220 Optical observations
  97. GRB 981226 Optical Observations
  98. GRB 981220 and GRB 981226, optical observations
  99. GRB981226 Optical Observations
  100. GRB981226 BeppoSAX follow up

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