Skip to main content
New! Super-Kamiokande JSON Notices and Schema v4.5.0. 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"

26362 results found.

  1. GRB 990506, optical observations from +1 to +3 hours
  2. GRB 990506, optical observations
  3. GRB990506 observation plan
  4. IPN localization for GRB990506
  5. GRB990323 PRECISE IPN POSITION
  6. GRB 990316 Optical Observations
  7. GRB 990316 optical observations
  8. GRB990316: simultaneous optical observation
  9. GRB990316 - Optical null results
  10. GRB990308 not a new SGR
  11. GRB 990308a and GRB 990308b
  12. GRB990308, Possible new SGR~0209+70
  13. GRB 990123, Field Photometry
  14. GRB 990217 Optical Observations
  15. BATSE Flight Anomaly
  16. GRB990217: BeppoSAX/GRBM data
  17. GRB990123 observations
  18. GRB990217 Optical observation
  19. GRB990123, Optical Observation
  20. GRB 990123: Discovery of the Probable Host Galaxy
  21. GRB 990123: Reduced HST Images
  22. GRB19990123 observations
  23. GRB 990123: BVRI standards in the field
  24. GRB981220, field photometry
  25. GRB990123, Optical observation
  26. GRB990123, 15-GHz limits
  27. GRB 990123: New Constraints on Possible Foreground Galaxies
  28. GRB990123 Optical Observations
  29. GRB990123, Probability of gravitational lensing
  30. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  31. GRB990123, Preliminary Lens Search Results
  32. On the Lensing Interpretation of GRB 990123
  33. Search for Potential Images of GRB 990123
  34. Search for Potential Images of GRB 990123
  35. GRB990123, Optical BVRI Observations
  36. GRB 990123: near-infrared observations.
  37. GRB990123, OSSE observations
  38. GRB990123: NIR Observation
  39. GRB990123, ASCA X-ray observation of afterglow
  40. "GRB 990123: New BV Observations"
  41. GRB 990123 Optical Follow-Up
  42. GRB 990123: BATSE Observations
  43. GRB990123 Optical Observations
  44. GRB 990123: New Optical Observations, Decay Measure
  45. GRB 990123 Optical Follow-Up
  46. GRB 990123: Possible Gravitationally Lensed Burst?
  47. GRB990123, optical observation
  48. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  49. GRB990123, Optical observation
  50. GRB 990123: Optical Decay Slope
  51. GRB 990123 r-band photometry
  52. GRB 990123 Optical Follow-up
  53. GRB990123, early optical counterpart detection
  54. GRB990123 Optical Observation
  55. Possible identification of SN1999E with GRB980910
  56. Optical Observations of GRB 981220
  57. GRB 981226: radio variable
  58. GRB981220
  59. GRB981220, Correction to GCN 179
  60. GRB 981220 Optical observations
  61. GRB 981226 Optical Observations
  62. GRB 981220 and GRB 981226, optical observations
  63. GRB981226 Optical Observations
  64. GRB981226 BeppoSAX follow up
  65. GRB 981226
  66. GRB 981226 optical observations
  67. GRB981220 B, R and I band observations
  68. Optical Observations of GRB981226
  69. GRB 981220:Optical Observations
  70. GRB 981226 optical observations
  71. GRB 981220
  72. GRB 981220, radio observations
  73. GRB981220 I-band Observations
  74. GRB 981220
  75. GRB 980326/Host Galaxy
  76. GRB 981220: RXTE/ASM and BeppoSAX/GRBM results
  77. BeppoSAX NFI Observation of GRB980425
  78. GRB980329 R,I flux calibration and R,I,K upper limits
  79. GRB980425 Optical Follow-up
  80. GRB 980923 BATSE Observations
  81. SGR1900+14, BeppoSAX-GRBM observations
  82. GRB970508 optical observations
  83. GRB971214, association with a Galactic star?
  84. GRB980519, Optical Observations
  85. GRB980703 - BeppoSAX/GRBM detection
  86. GRB980703 optical photometry
  87. GRB 980703: BATSE Observations
  88. GRB980703 optical observations
  89. GRB980703: Radio transient
  90. GRB 980703: Spectrum of the proposed optical counterpart
  91. GRB980703 Transient Optical Follow-Up
  92. GRB980703: LOTIS observation at early times
  93. GRB980613 Optical Observations
  94. GRB980703 (I band observations)
  95. BeppoSAX NFI observations of GRB 980703
  96. GRB980519 observation report
  97. GRB980703 optical followup
  98. Radio observations of SGRs
  99. SGR1900+14 field optical observations
  100. GRB980613, 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