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"

35957 results found.

  1. GRB 050408, SMARTS optical/IR afterglow observations
  2. GRB 050408: Optical limit at 20 min after the burst
  3. GRB 050408, optical observations
  4. GRB 050408: Moderate-resolution Gemini Spectroscopy
  5. GRB 050408,optical observation
  6. GRB 050408 Optical Observations
  7. GRB 050408: Emission and absorption redshift
  8. GRB 050408: Mercator Optical Observations
  9. GRB 050408: Magellan astrometry and photometry
  10. GRB 050408: First Optical observations with TFOSC at the RTT150
  11. GRB 050408: steepening of the optical decay
  12. GRB 050408: Optical afterglow confirmed
  13. GRB 050408: opitcal observation
  14. GRB 050408, optical observations
  15. GRB 050408 optical candidate
  16. GRB 050408: Swift XRT Position
  17. GRB 050408: ROTSE-III Optical Limits
  18. GRB 050408 (=H3711): A Long X-Ray-Rich GRB Detected by HETE
  19. GRB050408: MASTER optical observations
  20. GRB050401: Radio Detection
  21. Swift-UVOT Optical Counterpart Candidate to XRF 050406
  22. GRB 050406: Magellan optical observations
  23. GRB 050406: early Swift XRT analysis results
  24. GRB 050406 BAT refined analysis
  25. GRB 050406: Early observations with Swift-UVOT
  26. GRB 050406: Swift XRT Position
  27. Swift-BAT detection of GRB 050406
  28. Konus-Wind observation of GRB 050401
  29. GRB050401: Radio observation at 610 MHz with GMRT
  30. GRB 050401: VLT spectroscopic redshift
  31. GRB 050401 Optical Observations
  32. GRB 050401 BAT refined analysis
  33. Very questionable identity of Swift-BAT GRB050402 (Trig=113225)
  34. GRB050401: TNG R-band observation
  35. GRB 050402A: IR Analysis
  36. GRB 050402A: IR Observations
  37. GRB 050402: Early observations with Swift-UVOT
  38. Swift Trigger 113225: P60 Observations
  39. GRB 050401: Optical afterglow confirmed
  40. GRB 050401: Optical afterglow candidate
  41. Swift-BAT detection of GRB 050401
  42. GRB 050401: Prompt XRT position
  43. Retraction of three Swift GRB triggers
  44. GRB050331: No Afterglow Detected
  45. Swift-BAT detection of GRB 050331b
  46. GRB 050331: Swift UVOT Source
  47. Swift-BAT detection of GRB 050331
  48. GRB 050331: Swift XRT Position
  49. GRB050319: radio observation
  50. Konus-Wind observation of GRB 050326
  51. GRB 050326: Early observations with Swift-UVOT
  52. GRB 050326 XMM-Newton observation
  53. GRB 050326 : Planned XMM-Newton observation
  54. GRB 050326: Swift XRT Position
  55. GRB050326: optical limit 33min before GRB
  56. GRB 050326 BAT refined analysis
  57. GRB050326: delayed XRT observation
  58. Swift-BAT detection of a bright GRB 050326
  59. GRB050319, color indices
  60. GRB050319: RTT150 Optical Observations
  61. Swift-BAT trigger 112060 is not a real GRB
  62. GRB 050319: Absorption redshift from the Nordic Optical Telescope
  63. GRB 050319: ROTSE-III Refined Analysis
  64. GRB 050318: Swift-BAT refined analysis
  65. Refined Swift XRT positions for GRB050315, GRB050318 and GRB050319
  66. GRB050319: VLA Observations
  67. GRB 050319 R band observations
  68. GRB 050319: Swift-UVOT detection of the afterglow
  69. GRB 050315: Variability Analysis of Swift BAT Time History
  70. GRB050319: Radio Observations
  71. GRB 050319: NIR afterglow candidate
  72. GRB 050319:Near IR afterglow
  73. GRB 050318: SWIFT-UVOT refined analysis
  74. GRB 050318: Absorption redshift from Magellan
  75. GRB 050319: Optical observation
  76. GRB 050319 : Confirmation of optical afterglow decay
  77. GRB 050319: Swift-BAT refined analysis
  78. GRB050319,optical observation
  79. Swift Detection of GRB 050319
  80. GRB 050319: Detection of Possible Optical Counterpart
  81. GRB 050318: Swift/UVOT detection of afterglow emission
  82. GRB 050318: Magellan optical afterglow identification
  83. GRB050318: Swift XRT position
  84. RXTE Observations of GRB050318
  85. Swift-BAT detection of GRB 050318
  86. GRB 050315, SMARTS optical afterglow decay
  87. GRB050316: MASTER before, simultanious and follow up optical
  88. GRB 050306: ROTSE-III early limits
  89. GRB050316: MASTER optical observations
  90. GRB 050315: Swift-BAT further refined analysis
  91. GRB 050315, SMARTS optical/IR afterglow observations
  92. GRB 050315 I-band observations
  93. GRB050315: Radio afterglow
  94. GRB 050315: Absorption redshift
  95. GRB 050315: Optical afterglow identification
  96. GRB050315: Swift-BAT Refined analysis
  97. Non-detection of GRB050315 in ATCA Radio Observations
  98. GRB 050315: Swift XRT Position
  99. GRB 050219b: Gemini/GNIRS near-infrared spectroscopy
  100. GRB 050315: Early Observations with Swift/UVOT

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