Skip to main content
New! Browse Circulars by Event, Advanced Search, Sample Codes, Schema Release. 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"

25048 results found.

  1. BATSE Flight Anomaly
  2. GRB990217: BeppoSAX/GRBM data
  3. GRB990123 observations
  4. GRB990217 Optical observation
  5. GRB990123, Optical Observation
  6. GRB 990123: Discovery of the Probable Host Galaxy
  7. GRB 990123: Reduced HST Images
  8. GRB19990123 observations
  9. GRB 990123: BVRI standards in the field
  10. GRB981220, field photometry
  11. GRB990123, Optical observation
  12. GRB990123, 15-GHz limits
  13. GRB 990123: New Constraints on Possible Foreground Galaxies
  14. GRB990123 Optical Observations
  15. GRB990123, Probability of gravitational lensing
  16. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  17. GRB990123, Preliminary Lens Search Results
  18. On the Lensing Interpretation of GRB 990123
  19. Search for Potential Images of GRB 990123
  20. Search for Potential Images of GRB 990123
  21. GRB990123, Optical BVRI Observations
  22. GRB 990123: near-infrared observations.
  23. GRB990123, OSSE observations
  24. GRB990123: NIR Observation
  25. GRB990123, ASCA X-ray observation of afterglow
  26. "GRB 990123: New BV Observations"
  27. GRB 990123 Optical Follow-Up
  28. GRB 990123: BATSE Observations
  29. GRB990123 Optical Observations
  30. GRB 990123: New Optical Observations, Decay Measure
  31. GRB 990123 Optical Follow-Up
  32. GRB 990123: Possible Gravitationally Lensed Burst?
  33. GRB990123, optical observation
  34. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  35. GRB990123, Optical observation
  36. GRB 990123: Optical Decay Slope
  37. GRB 990123 r-band photometry
  38. GRB 990123 Optical Follow-up
  39. GRB990123, early optical counterpart detection
  40. GRB990123 Optical Observation
  41. Possible identification of SN1999E with GRB980910
  42. Optical Observations of GRB 981220
  43. GRB 981226: radio variable
  44. GRB981220
  45. GRB981220, Correction to GCN 179
  46. GRB 981220 Optical observations
  47. GRB 981226 Optical Observations
  48. GRB 981220 and GRB 981226, optical observations
  49. GRB981226 Optical Observations
  50. GRB981226 BeppoSAX follow up
  51. GRB 981226
  52. GRB 981226 optical observations
  53. GRB981220 B, R and I band observations
  54. Optical Observations of GRB981226
  55. GRB 981220:Optical Observations
  56. GRB 981226 optical observations
  57. GRB 981220
  58. GRB 981220, radio observations
  59. GRB981220 I-band Observations
  60. GRB 981220
  61. GRB 980326/Host Galaxy
  62. GRB 981220: RXTE/ASM and BeppoSAX/GRBM results
  63. BeppoSAX NFI Observation of GRB980425
  64. GRB980329 R,I flux calibration and R,I,K upper limits
  65. GRB980425 Optical Follow-up
  66. GRB 980923 BATSE Observations
  67. SGR1900+14, BeppoSAX-GRBM observations
  68. GRB970508 optical observations
  69. GRB971214, association with a Galactic star?
  70. GRB980519, Optical Observations
  71. GRB980703 - BeppoSAX/GRBM detection
  72. GRB980703 optical photometry
  73. GRB 980703: BATSE Observations
  74. GRB980703 optical observations
  75. GRB980703: Radio transient
  76. GRB 980703: Spectrum of the proposed optical counterpart
  77. GRB980703 Transient Optical Follow-Up
  78. GRB980703: LOTIS observation at early times
  79. GRB980613 Optical Observations
  80. GRB980703 (I band observations)
  81. BeppoSAX NFI observations of GRB 980703
  82. GRB980519 observation report
  83. GRB980703 optical followup
  84. Radio observations of SGRs
  85. SGR1900+14 field optical observations
  86. GRB980613, optical observations
  87. GRB 980613: Optical transient and its host galaxy
  88. SGR1627-41, RXTE/ASM observations
  89. GRB 980613: Detection of the probable host galaxy
  90. Reduced error box of SGR 1627-41
  91. GRB 980613: BATSE Observations
  92. GRB 980613 Optical Observations
  93. GRB 980613 optical observations
  94. Discovery of a new SGR source, SGR1627-41
  95. GRB980613 Optical Observations
  96. GRB980613 observations from Palomar
  97. GRB 980613 optical/IR obs.
  98. GRB980613 Near Infra-Red Observations
  99. GRB971214 Secondary Standards
  100. GRB980519 Secondary Standards

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