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"

18334 results found.

  1. GRB 051210: SALT detection limit
  2. GRB 051210: FRAM early limit
  3. GRB051210: Swift UVOT Observation
  4. GRB 051210: Swift detection of a burst
  5. An extraordinary long burst on December 3 from SGR1806-20
  6. Possible resuming of the SGR 1806-20 activity
  7. GRB051117b: No Swift/UVOT Detection
  8. GRB 051117A: Swift/UVOT Detection of an Afterglow
  9. GRB 051109A : GAO 150cm telescope Rc-band detection
  10. GRB 051117B: R and I observations of possible host galaxy
  11. GRB 051117B,optical observation
  12. GRB 051117B: Lulin R and I band observation
  13. GRB051114: results of the Swift-XRT observation
  14. GRB 051109B : Nainital upper limits
  15. GRB 051114: Radio Observations
  16. GRB050925: analysis of the XMM-Newton observation
  17. GRB051109A optical observations
  18. GRB 051111: Radio afterglow
  19. GRB051103: Radio Observations
  20. GRB051111: Swift/UVOT Observations
  21. GRB051111: XRT preliminary analysis
  22. GRB 051109A Optical Observations
  23. GRB 051111a: IR photometry
  24. GRB 051109B. Radio Observations
  25. GRB 051109A
  26. GRB051109A - radio observations
  27. Early RAPTOR measurements of GRB 051109a - the movie.
  28. GRB 051109A: Swift-UVOT Observations
  29. GRB051109B: no UVOT source detected
  30. GRB 051109B: Super-LOTIS Observations
  31. GRB051105B: REM Optical observation
  32. GRB 051109: HET Optical Spectrum and Absorption Redshift
  33. GRB 051109: Rc and Ic observations
  34. GRB 051109: Swift-BAT refined analysis
  35. GRB 051109a: IR Photometry and Astrometry
  36. GRB051109: Swift detection of a burst
  37. GRB 051109a: IR Detections
  38. GRB051105B: Swift/XRT upper limit
  39. GRB051105B: Swift/UVOT upper limit
  40. GRB051103: optical observations
  41. GRB051103: MASTER: OT limit and host galaxy candidates
  42. GRB 051105a, observation from Naini Tal and OSN
  43. GRB 051105a: MDM Observations
  44. GRB 051105A: TNG optical observations
  45. GRB051105A: Swift/UVOT Observations
  46. GRB 051105A, radio observations
  47. XRT observations of GRB 051105A
  48. GRB 051105: Swift detection of a short burst
  49. Recent GRB UBVRcIc field photometry
  50. GRB051028 SARA Observation
  51. GRB051028: Swift/UVOT upper limits
  52. GRB051028: Swift XRT Position
  53. GRB051028:MASTER observations
  54. GRB051021B: Swift/UVOT Upper limits
  55. GRB 051021, Optical Observations
  56. GRB051012: Swift-XRT analysis
  57. GRB 051022: Swift/UVOT Upper Limits
  58. GRB051022: Radio Counterpart
  59. GRB051022: IR observations
  60. GRB051021A: Swift XRT refined analysis
  61. GRB051022: Optical Observations
  62. GRB051021b: Magellan IR Imaging
  63. GRB 051021, SMARTS optical/IR observations
  64. GRB051022: Swift XRT Position
  65. GRB 051021: P200 Ks Observations
  66. GRB 051022 (=H3950): SXC Flight Localization is Valid
  67. GRB051021: Swift/UVOT Upper Limits
  68. GRB 051022: SSO40 Optical Observations
  69. GRB051022,optical observation
  70. GRB 051021,optical observation
  71. GRB 051021B: Swift detection of a burst
  72. GRB 051021: Optical observations and candidate afterglow
  73. Swift-BAT triggered on a posible CR Shower or possible GRB
  74. Afterglow candidate of GRB 051016B observed at Lulin
  75. GRB 051016A: Swift/UVOT upper limits
  76. GRB 051016B: Swift/UVOT detection
  77. GRB 051016B,optical observation
  78. GRB 051016B: Swift detection of a soft burst
  79. GRB051016 XMM-Newton observation
  80. GRB 051016: PROMPT Observations
  81. GRB051016: Swift detection of a burst
  82. GRB 051012: Swift-BAT detection of burst yesterday
  83. GRB 051006: Swift/UVOT Upper Limits
  84. GRB051008: Radio Observation
  85. GRB 051008, optical observations
  86. GRB 051008: early Swift XRT analysis
  87. GRB 051008: Swift UVOT Candidate
  88. GRB 051006: P60 Observations
  89. Swift-BAT trigger 158700 is a probable Cosmic Ray Shower Event
  90. GRB051006: Swift detection of a burst
  91. GRB 050906, summary of radio observations
  92. GRB051001: Swift UVOT Upper Limits
  93. GRB 051001: AAT infra-red observations
  94. GRB 051001: Swift Detection of a Burst
  95. GRB 050820A: NIR photometry at the TNG
  96. GRB/SGR 050925: IR Observations
  97. GRB050925: Swift UVOT upper limits
  98. GRB050925: Faulkes Telescope North R-band limit
  99. GRB050925: Swift-BAT detection of a short burst
  100. GRB050922B: Swift UVOT early upper limits.

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