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"
  1. GRB 060110: ROTSE-III Confirmation of Optical Counterpart
  2. GRB 060110: IR Candidate Afterglow
  3. GRB060110, optical observation
  4. GRB 060110: Super-LOTIS observations
  5. GRB 060110: Optical observation
  6. GRB 060110: Correction
  7. Correction to GRB 060109 XRT analysis
  8. GRB 050110: IR Observations
  9. GRB 060110: Optical limit
  10. GRB 060110: Swift-BAT detection of a burst
  11. GRB 060109: Refined Swift-XRT analysis
  12. GRB 060109: Swift/UVOT upper limits
  13. GRB060109, optical observation
  14. GRB 060108: ISAS early observations and near IR upper limit
  15. GRB060108: P200 Ks Observations
  16. GRB 060108: early UKIRT K-band observations
  17. Swift UVOT correction to GCN 4455
  18. GRB 060109: Swift Detection of a long burst
  19. GRB 060108: a dark burst?
  20. GRB 060108: Refined XRT analysis
  21. GRB 060108: VLT J-band observations
  22. GRB 060108: Mitsume optical observations
  23. GRB 060108: Swift/UVOT upper limits
  24. GRB 060105: quick look analysis of the Suzaku/XIS afterglow observation
  25. GRB060108: SDSS pre-burst observations
  26. GRB060108: Faulkes Telescope observation
  27. GRB060108, optical observation
  28. GRB 060108: Refined analysis of the Swift-BAT burst
  29. GRB 060108: Swift XRT position
  30. GRB060108: Swift detection of its 100th GRB
  31. GRB 060105: pseudo-z from spectral parameters of the prompt emission
  32. GRB 060105: Radio observations
  33. GRB 060105: MDM Observation
  34. Konus-Wind observation of GRB 060105
  35. GRB 060105: ISAS observations and near IR upper limit
  36. GRB 060105: Swift/UVOT upper limits
  37. GRB 060105: Mitsume optical observations
  38. GRB 060105: BAT refined analysis
  39. GRB 060102 - no XRT afterglow
  40. GRB 060105: XRT refined analysis
  41. GRB060105: Suzaku-XIS and -HXD observation plan
  42. GRB060105, optical observation
  43. GRB060105 : Kiso optical observation
  44. GRB060105: Swift detection of a bright long burst
  45. Swift-BAT trigger 175653 is not an astrophysical source
  46. GRB 060102: MDM Observation
  47. Swift-BAT trigger 175653 is probably not a GRB
  48. GRB 060102: Swift-BAT refined analysis
  49. Time Correction to GRB 060102
  50. GRB 060102: Swift-BAT detection of a burst
  51. GRB051211B: optical observations
  52. GRB051227: SARA Observations
  53. GRB 051221B: Optical Observations with Kuiper 1.54m
  54. GRB 051227: Likely host galaxy underlying afterglow position
  55. GRB 051227: optical observation
  56. GRB051221B: Radio observations
  57. GRB 051221A: VLA Radio Observations
  58. GRB051227: Radio Observations
  59. GRB 051227: Confirmed fading from Gemini observations
  60. GRB051227: further analysis of VLT images
  61. GRB 051227: optical afterglow
  62. GRB 051227: Swift/UVOT Upper Limits (Possible U-band
  63. GRB 051227: Gemini observations
  64. GRB 051227: Keck Spectroscopy
  65. GRB 051227: Magellan r'-band Imaging/Astrometry
  66. GRB 051227: refined analysis of VLT images
  67. GRB 051227: P60 Observations
  68. GRB 051227: MDM Observation
  69. GRB 051227: R-band object in the XRT error circle
  70. GRB 051227: Joint Swift-HETE Spectral Analysis
  71. GRB 051227: XRT refined analysis
  72. GRB 051227: Further analysis of the Swift-BAT burst
  73. GRB 051227: Refined analysis of the Swift-BAT burst
  74. GRB051227: SDSS pre-burst observations
  75. GRB 051227, optical observation
  76. GRB 051227: Swift detection of a burst
  77. GRB051117B: optical observation
  78. IBAS_alert n. 2719 : not a real GRB
  79. Konus-Wind observation of GRB 051221A
  80. GRB051221A: Suzaku WAM observation of the prompt emission
  81. GRB 051221A: MDM Optical Observations
  82. GRB051016: analysis of the XMM-Newton observation
  83. GRB 051221A: Detection at 251nm with Swift UVOT
  84. GRB 051221A: Chandra Afterglow Position
  85. GRB 051221A: Refined spectral and temporal analysis of the Swift-BAT short hard burst
  86. GRB 051221B: ROTSE-III Optical Limits
  87. GRB 051221B: TAROT optical limits
  88. GRB 051221A: WSRT Radio Observations
  89. GRB 051221: Redshift from Gemini
  90. GRB 051221: Continued fading of optical afterglow
  91. GRB 051221B: Refined analysis of the Swift-BAT burst
  92. Possible GRB 051221B: MDM Optical Detection
  93. GRB 051221A: RAPTOR Fading Counterpart Constraint
  94. GRB 051221B: BOOTES optical observations.
  95. Possible GRB 051221B: Swift XRT position
  96. GRB 051211A: Evidence This Is a Short Burst from Analysis of Spectral
  97. Swift-BAT detection of a possible burst
  98. GRB 051221: Discovery of fading optical afterglow
  99. GRB 051221: Swift XRT refined analysis
  100. GRB 051221: Swift/UVOT upper limits

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