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"

38354 results found.

  1. GRB990308 not a new SGR
  2. GRB 990308a and GRB 990308b
  3. GRB990308 (Trig. 7457), optical observations
  4. GRB990308, Possible new SGR~0209+70
  5. GRB981220, IPN localization
  6. GRB 981220, radio observations
  7. GRB 990217 Optical Observations
  8. GRB 990217, radio observations
  9. BATSE Flight Anomaly
  10. GRB990217: BeppoSAX/GRBM data
  11. Optical Observations of GRB990217
  12. GRB990123: Caltech STIS Photometry and Images
  13. GRB990123 observations
  14. GRB990217 Optical observation
  15. GRB990217, WFC position
  16. GRB990123, Optical Observation
  17. GRB 990123: Discovery of the Probable Host Galaxy
  18. GRB 990123: Reduced HST Images
  19. GRB19990123 observations
  20. GRB 990123: Updated Keck Spectroscopy Results
  21. GRB981220, field photometry
  22. GRB 990123 NOT Spectrum Update
  23. GRB990123, Optical observation
  24. GRB990123, is the "radio flare" due to an inhomogeneous medium?
  25. GRB 990123: Publicly available reduced HST images
  26. GRB990123, Upcoming HST Service Observations
  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. GRB 990123: Continued Radio Observations
  32. GRB990123, Preliminary Lens Search Results
  33. On the Lensing Interpretation of GRB 990123
  34. Search for Potential Images of GRB 990123
  35. Search for Potential Images of GRB 990123
  36. GRB990123, Optical BVRI Observations
  37. GRB 990123: near-infrared observations.
  38. GRB990123, OSSE observations
  39. GRB 990123: Strong MeV CGRO-COMPTEL detection now posted on WWW
  40. GRB990123: NIR Observation
  41. "GRB 990123: New BV Observations"
  42. GRB 990123 Optical Follow-Up
  43. GRB 990123: BATSE Observations
  44. GRB 990123 Keck Spectrum update
  45. GRB990123 IPN annulus
  46. GRB 990123 : Multiple and Distorted Images of the Host Galaxy?
  47. GRB 990123 Spectroscopic Redshifts
  48. GRB 990123: New Optical Observations, Decay Measure
  49. GRB 990123 Optical Follow-Up
  50. GRB 990123: Possible Gravitationally Lensed Burst?
  51. GRB990123, optical observation
  52. GRB 990123 optical observations
  53. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  54. GRB 990123 radio observations
  55. GRB 990123, new radio source
  56. GRB990123 optical observations
  57. GRB990123, Optical observation
  58. GRB 990123: Optical Decay Slope
  59. GRB 990123 r-band photometry
  60. GRB 990123 Optical Follow-up
  61. GRB990123, early optical counterpart detection
  62. GRB990123 Optical Observation
  63. GRB990123, BeppoSAX-NFI X-ray afterglow detection
  64. GRB990123, refined SAX-WFC position
  65. GRB 990123: Bright New Source, Possible Optical Transient
  66. GRB 990123, Radio observations
  67. GRB990123, BeppoSAX WFC detection and NFI planned follow-up
  68. Possible identification of SN1999E with GRB980910
  69. Optical Observations of GRB 981220
  70. GRB 981226: radio variable
  71. GRB981220
  72. GRB981220, Optical Observations
  73. GRB 981220 Optical observations
  74. GRB 981226 Optical Observations
  75. GRB 980613: Spectroscopy of the host galaxy
  76. GRB981226, sub-millimeter observations
  77. GRB981220, sub-millimeter observations
  78. GRB 981220 and GRB 981226, optical observations
  79. GRB981226 Optical Observations
  80. GRB981226 BeppoSAX follow up
  81. GRB 981226 radio observations
  82. GRB 981226
  83. GRB 981226 optical observations
  84. radio observations of GRB 981226
  85. GRB981220 B, R and I band observations
  86. GRB981226, BeppoSAX-NFI follow-up
  87. Optical Observations of GRB981226
  88. GRB 981220:Optical Observations
  89. GRB981226, BeppoSAX Christmas GRB
  90. GRB 981226 - Infrared Observations
  91. GRB 981220
  92. GRB 981220, radio observations
  93. GRB981226 Optical Observation
  94. GRB 981220, radio observations
  95. GRB 981220: BeppoSAX/GRBM results
  96. GRB981220 I-band Observations
  97. GRB981220 Optical Observations
  98. GRB 981220
  99. GRB 981220 Optical Observations
  100. GRB 981220, 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