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"

24601 results found.

  1. GRB990704 radio and optical observations
  2. GRB990704
  3. GRB990704, optical observations
  4. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  5. Optical Observations of GRB990627
  6. BeppoSAX: GRB990625
  7. Late-time HST/STIS Observation of GRB 990123
  8. Optical Observations of GRB 990506
  9. GRB990527 Optical Observations
  10. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  11. Late Afterglows of GRBs 990510, 990123
  12. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  13. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  14. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  15. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  16. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  17. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  18. radio observations of X-ray/GRB transient field
  19. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  20. Optical report on X-ray/GRB transient
  21. radio detection of X-ray/GRB transient
  22. BeppoSAX: A new fast X-ray transient
  23. GRB 990510: optical observations
  24. GRB 990510: optical linear polarization
  25. GRB 990510: optical observations
  26. GRB990510: X-ray afterglow
  27. GRB 990510: Broad Band Break
  28. GRB 990510: BATSE Observations
  29. GRB 990510: BeppoSAX/GRBM observations
  30. GRB990510 optical observations
  31. GRB 990510 optical observations
  32. GRB 990506 Radio Observations
  33. GRB 990123, optical monitoring
  34. GRB 990506: BATSE Observations
  35. GRB 990506, optical observations
  36. GRB 990506, Optical Observations
  37. GRB 990506 optical observations
  38. GRB 990506, optical observations
  39. GRB 990506, armchair astronomy
  40. GRB 990506, optical observations from +1 to +3 hours
  41. GRB 990506, optical observations
  42. GRB990506 observation plan
  43. IPN localization for GRB990506
  44. GRB990323 PRECISE IPN POSITION
  45. GRB 990316 Optical Observations
  46. GRB 990316 optical observations
  47. GRB990316: simultaneous optical observation
  48. GRB990316 - Optical null results
  49. GRB990308 not a new SGR
  50. GRB 990308a and GRB 990308b
  51. GRB990308, Possible new SGR~0209+70
  52. GRB 990123, Field Photometry
  53. GRB 990217 Optical Observations
  54. BATSE Flight Anomaly
  55. GRB990217: BeppoSAX/GRBM data
  56. GRB990123 observations
  57. GRB990217 Optical observation
  58. GRB990123, Optical Observation
  59. GRB 990123: Discovery of the Probable Host Galaxy
  60. GRB 990123: Reduced HST Images
  61. GRB19990123 observations
  62. GRB 990123: BVRI standards in the field
  63. GRB981220, field photometry
  64. GRB990123, Optical observation
  65. GRB990123, 15-GHz limits
  66. GRB 990123: New Constraints on Possible Foreground Galaxies
  67. GRB990123 Optical Observations
  68. GRB990123, Probability of gravitational lensing
  69. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  70. GRB990123, Preliminary Lens Search Results
  71. On the Lensing Interpretation of GRB 990123
  72. Search for Potential Images of GRB 990123
  73. Search for Potential Images of GRB 990123
  74. GRB990123, Optical BVRI Observations
  75. GRB 990123: near-infrared observations.
  76. GRB990123, OSSE observations
  77. GRB990123: NIR Observation
  78. GRB990123, ASCA X-ray observation of afterglow
  79. "GRB 990123: New BV Observations"
  80. GRB 990123 Optical Follow-Up
  81. GRB 990123: BATSE Observations
  82. GRB990123 Optical Observations
  83. GRB 990123: New Optical Observations, Decay Measure
  84. GRB 990123 Optical Follow-Up
  85. GRB 990123: Possible Gravitationally Lensed Burst?
  86. GRB990123, optical observation
  87. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  88. GRB990123, Optical observation
  89. GRB 990123: Optical Decay Slope
  90. GRB 990123 r-band photometry
  91. GRB 990123 Optical Follow-up
  92. GRB990123, early optical counterpart detection
  93. GRB990123 Optical Observation
  94. Possible identification of SN1999E with GRB980910
  95. Optical Observations of GRB 981220
  96. GRB 981226: radio variable
  97. GRB981220
  98. GRB981220, Correction to GCN 179
  99. GRB 981220 Optical observations
  100. GRB 981226 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