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"

19549 results found.

  1. GRB990704
  2. GRB990704: BeppoSAX detection
  3. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  4. GRB 990627, radio observations
  5. Late-time HST/STIS Observation of GRB 990123
  6. Optical Observations of GRB 990506
  7. GRB 990506 Radio Transient
  8. GRB990527 Optical Observations
  9. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  10. IPN error box for GRB990527
  11. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  12. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  13. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  14. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  15. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  16. radio observations of X-ray/GRB transient field
  17. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  18. Optical report on X-ray/GRB transient
  19. radio detection of X-ray/GRB transient
  20. GRB 990510: optical linear polarization
  21. GRB 990510: optical observations
  22. GRB990510: X-ray afterglow
  23. GRB 990510 optical observations
  24. GRB990510: NFI X-ray source
  25. GRB 990506 Radio Observations
  26. GRB 990123, optical monitoring
  27. GRB 990506, optical observations
  28. GRB 990510: Final BeppoSAX-WFC Coordinates
  29. GRB 990506, Optical Observations
  30. GRB 990506 optical observations
  31. GRB 990506 optical observations
  32. GRB 990506, optical observations
  33. GRB990506 observation plan
  34. GRB 990506, optical observations from +1 to +3 hours
  35. GRB 990506, optical observations
  36. GRB990506 observation plan
  37. GRB 990316 Optical Observations
  38. GRB 990316 optical observations
  39. GRB990316: simultaneous optical observation
  40. GRB990308, Possible new SGR~0209+70
  41. GRB 990123, Field Photometry
  42. GRB 990217 Optical Observations
  43. BATSE Flight Anomaly
  44. GRB990217: BeppoSAX/GRBM data
  45. GRB990123 observations
  46. GRB990123, Optical Observation
  47. GRB 990123: Discovery of the Probable Host Galaxy
  48. GRB19990123 observations
  49. GRB 990123: BVRI standards in the field
  50. GRB981220, field photometry
  51. GRB990123, Optical observation
  52. GRB 990123: Publicly available reduced HST images
  53. GRB990123, Upcoming HST Service Observations
  54. GRB990123, 15-GHz limits
  55. GRB 990123: New Constraints on Possible Foreground Galaxies
  56. GRB990123 Optical Observations
  57. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  58. GRB 990123: Continued Radio Observations
  59. GRB990123, Preliminary Lens Search Results
  60. Search for Potential Images of GRB 990123
  61. GRB990123, Optical BVRI Observations
  62. GRB 990123: near-infrared observations.
  63. GRB990123, OSSE observations
  64. GRB990123: NIR Observation
  65. "GRB 990123: New BV Observations"
  66. GRB 990123: New Optical Observations, Decay Measure
  67. GRB 990123 Optical Follow-Up
  68. GRB 990123: Possible Gravitationally Lensed Burst?
  69. GRB990123, optical observation
  70. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  71. GRB 990123 r-band photometry
  72. GRB 990123 Optical Follow-up
  73. Optical Observations of GRB 981220
  74. GRB 981226: radio variable
  75. GRB 981226 Optical Observations
  76. GRB981226 BeppoSAX follow up
  77. GRB 981226
  78. GRB 981226 optical observations
  79. GRB 981220:Optical Observations
  80. GRB981226, BeppoSAX Christmas GRB
  81. GRB 981226 optical observations
  82. GRB 981220, radio observations
  83. GRB 981220
  84. GRB 980326/Host Galaxy
  85. BeppoSAX NFI Observation of GRB980425
  86. GRB980329 R,I flux calibration and R,I,K upper limits
  87. GRB980425 Optical Follow-up
  88. GRB970508 optical observations
  89. GRB980519, Optical Observations
  90. GRB 980703 (NFI observations)
  91. GRB980703 optical photometry
  92. GRB980703 optical observations
  93. GRB980703: Radio transient
  94. GRB980703 Transient Optical Follow-Up
  95. GRB980703: LOTIS observation at early times
  96. BeppoSAX NFI observations of GRB 980703
  97. GRB980703 optical followup
  98. SGR1627-41
  99. Radio observations of SGRs
  100. SGR1900+14 field optical observations

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