Skip to main content
New! BOOM Notices and Schema v7.0.0. 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"

44268 results found.

  1. GRB 120202A: MASTER early optical observations
  2. LS I +61 303: Swift-BAT refined analysis
  3. GRB 120202A: D50 optical limits
  4. Swift detection of a burst from LS I +61 303
  5. GRB 120202A: GROND observations
  6. GRB 120202A: WHT, Gemini & UKIRT candidate afterglow
  7. GRB 120202A: Swift/XRT and UVOT observations
  8. GRB 120202A: TAROT Calern observatory optical observations
  9. GRB 120202A: A long GRB detected by INTEGRAL
  10. GRB 111228A: Possible host detected by Swift/UVOT
  11. GRB 120129A: MASTER optical observations
  12. GRB 120116A, the review of the sky area in plate archives
  13. Konus-Wind observation of GRB 120129A
  14. IPN Triangulation of GRB 120129A (long/intense)
  15. GRB 120127A / P48 Imaging
  16. GRB 120127A: MASTER optical observations
  17. GRB 120127A: MAXI/GSC detection of a probable GRB
  18. GRB 120118B: optical upper limit
  19. GRB 120116A: optical upper limit
  20. GRB 120119A : LOAO Optical Observations
  21. GRB 120119A : SMA submm follow-up observation
  22. Fermi GBM trigger 120123.169 is not a GRB
  23. GRB 120119A: EVLA observations
  24. GRB 120119A: GRT detection of early afterglow
  25. GRB 111225A: optical observations
  26. GRB 120119A: optical upper limit
  27. GRB 120121A: Swift/UVOT Upper Limits
  28. GRB 120121A: Swift-XRT refined Analysis
  29. GRB 120121A: Swift-BAT refined analysis
  30. GRB 120121A: Enhanced Swift-XRT position
  31. GRB 120121A: ISON-NM optical observations
  32. GRB 120121A: Swift-XRT position
  33. GRB 120121A: Swift detection of a burst
  34. GRB 120119A, Swift-BAT refined analysis
  35. GRB 120119A: TAROT La Silla observatory optical observations
  36. GRB120119A: REM NIR observations
  37. GRB 120119A: optical observations
  38. GRB 120119A: Swift/UVOT Observations
  39. GRB 120118B: RTT150 optical observations
  40. GRB 120119A: SMARTS optical/IR afterglow observations
  41. GRB 120119A: Swift-XRT refined Analysis
  42. GRB 120119A: Enhanced Swift-XRT position
  43. GRB 120102A, the review of the sky area in plate archive
  44. GRB 120119A: Fermi GBM observation
  45. GRB 120118B, Swift-BAT refined analysis
  46. Konus-Wind observation of GRB 120119A
  47. GRB 120119A: optical observations
  48. GRB 120118B: TNG NIR observations
  49. GRB 120118B: Swift-XRT refined Analysis
  50. GRB 120118B : Lulin Optical limit
  51. GRB 120119A: MMT redshift confirmation
  52. GRB 120119A: Lick 3m Spectroscopy
  53. GRB 120119A: Gemini-S redshift
  54. GRB 120119A: PROMPT optical observation of early afterglow
  55. GRB 120119A: GROND Detection of the Optical/NIR Afterglow
  56. GRB 120118B: Swift/UVOT Upper Limits
  57. GRB 120119A: Liverpool Telescope afterglow detection
  58. GRB 120119A: PAIRITEL NIR Detection
  59. GRB 120119A: Swift detection of a burst with an optical counterpart
  60. GRB 120118B: NOT observations
  61. GRB 120118B: Enhanced Swift-XRT position
  62. GRB 120118B: Faulkes Telescope South observations
  63. XRF 120118A: early optical limit by "Pi of the Sky"
  64. GRB 120118B: Swift-XRT position
  65. GRB 120118B: MASTER optical observations
  66. GRB 120118B: Swift detection of a burst
  67. XRF 120118A: Optical candidate
  68. XRF 120118A: further INTEGRAL analysis
  69. XRF 120118A: an X-Ray Flash detected by INTEGRAL
  70. GRB 120116A: Swift/UVOT Upper Limits
  71. GRB 120116A: Swift-XRT refined Analysis
  72. GRB 120116A: Enhanced Swift-XRT position
  73. AXP 4U 1042+61: Mondy optical observations
  74. GRB 120116A: Mondy optical observations
  75. GRB 120116A: Gemini optical/IR candidate
  76. GRB 120116A: EVLA observations
  77. GRB 120116A: WHT optical observations
  78. GRB 120116A: Optical observations at Crni Vrh
  79. GRB 120116A: Swift-BAT refined analysis
  80. GRB 120116A: NOT observations
  81. GRB 120116A: IAC80 I-band observations
  82. GRB 120116A: Bassano Bresciano Observatory optical observations
  83. GRB 120116A: MASTER Early optical limit
  84. GRB 120116A: Swift detection of a burst
  85. GRB 120114A found in ground analysis of BAT data
  86. GRB 111228A: optical observations
  87. AXP 4U 0142+61: Swift-BAT refined analysis (trigger 511611)
  88. GRB 120106A: optical upper limit
  89. Swift detection of an SGR burst from AXP 4U 0142+61
  90. GRB 120107A: Suzaku WAM observation of the prompt emission
  91. GRB 110915B, the review of the sky area in plate archives
  92. GRB 120107A: Fermi GBM observation
  93. GRB 120106A: MITSuME Okayama Optical Observation (update)
  94. Konus-Wind observation of GRB 120107A
  95. IPN Triangulation of GRB 120107A
  96. GBM trigger 347620337 (GRB 120107A?) : High-energy photon emission in Fermi/LAT data
  97. GRB 120106A: Swift/UVOT Upper Limits
  98. GRB 120106A: Bassano Bresciano Observatory optical observations
  99. GRB 120106A: MITSuME Okayama Ks-band upper limit
  100. GRB 120106A: MASTER Early OT marginally detection

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