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"

3028 results found.

  1. IceCube-200425A: No significant detection in HAWC
  2. GRB 200423A: Fermi GBM Final Real-time Localization
  3. Fermi GRB 200421A: Global MASTER-Net observations report
  4. GRB 200421A: Fermi GBM Final Real-time Localization
  5. Fermi trigger No 608935505: Global MASTER-Net observations report
  6. GRB 200415A: MASTER imspection and possible localisation
  7. GRB 200416A: Swift detection of a burst with an optical afterglow
  8. Konus-Wind observation of GRB 200412A
  9. Baksan Neutrino Observatory Alert 200408.26: Global MASTER-Net observations report
  10. Swift GRB 200409A: Global MASTER-Net observations report
  11. Fermi GRB 200407A: Global MASTER-Net observations report
  12. Baksan Neutrino Observatory Alert 200406.3: Global MASTER-Net observations report
  13. Fermi GRB 200405A: Global MASTER-Net observations report
  14. Fermi GRB 200403B: Global MASTER-Net observations report
  15. Fermi GRB 200403A: Global MASTER-Net observations report
  16. Fermi GRB 200402C: Global MASTER-Net observations report
  17. Fermi GRB 200401A: Global MASTER-Net observations report
  18. GRB 200325B: Mondy continued observations
  19. Fermi trigger No 606918292: Global MASTER-Net observations report
  20. GRB 200326A: Fermi GBM Final Real-time Localization
  21. Fermi trigger No 606681997: Global MASTER-Net observations report
  22. LIGO/Virgo S200316bj: no counterpart candidate in SVOM/GWAC-F30 observations
  23. Fermi trigger No 606263732: Global MASTER-Net observations report
  24. LIGO/Virgo S200316bj : No significant candidates in TAROT - FRAM - GRANDMA observations.
  25. LIGO/Virgo S200316bj: Upper limits from Insight-HXMT/HE observations
  26. LIGO/Virgo S200316bj: no counterpart candidate in SVOM/GWAC observations
  27. LIGO/Virgo S200316bj: No Counterparts in DDOTI/OAN Optical Observations
  28. LIGO/Virgo S200316bj: no counterpart candidates in the Swift/BAT observations
  29. SGR Swift J1818.0-1607: BOOTES-4/MET optical limit
  30. Fermi trigger No 605756501: Global MASTER-Net observations report
  31. Swift-BAT trigger 960986: Swift detection of a new SGR Swift J1818.0-1607
  32. Fermi trigger No 605632577: Global MASTER-Net observations report
  33. GRB 200310A: MAXI/GSC detection
  34. LIGO/Virgo S200302c : No significant candidates in FRAM - TAROT - GRANDMA observations.
  35. GRB 200303A: Fermi GBM Final Real-time Localization
  36. LIGO/Virgo S200302c: No counterpart candidates in KAIT observations
  37. LIGO/Virgo S200302c: no counterpart candidates in the Swift/BAT observations
  38. LIGO/Virgo S200224ca: Transient found in Swift/UVOT counterpart search
  39. LIGO/Virgo S200225q : No significant candidates in TAROT - FRAM - GRANDMA observations.
  40. LIGO/Virgo S200213t: No significant EM counterparts identified from continued GECKO observation of host galaxy candidates
  41. GRB 200227A: Mondy optical upper limit
  42. LIGO/Virgo S200224ca : No significant candidates in TAROT - FRAM - GRANDMA observations
  43. LIGO/Virgo S200224car: GRAWITA VST-ESO PARANAL observations.
  44. LIGO/Virgo S200225q: no counterpart candidates in the Swift/BAT observations
  45. LIGO/Virgo S200224ca: no counterpart candidates in the Swift/BAT observations
  46. GRB 200224B: DDOTI/OAN optical observations report
  47. LIGO/Virgo S200224ca: No counterpart candidates in KAIT observations
  48. LIGO/Virgo S200224ca: GRAWITA-Campo Imperatore observations.
  49. Fermi trigger No 604231129: Global MASTER-Net observations report
  50. GRB 200224C: Fermi GBM Final Real-time Localization
  51. GRB 200223A: Fermi GBM Final Real-time Localization
  52. LIGO/Virgo S200219ac: no counterpart candidate in SVOM/GWAC-F30 observations
  53. LIGO/Virgo S200219ac : No significant candidates in TAROT - FRAM - GRANDMA observations.
  54. LIGO/Virgo S200219ac: No counterpart candidates in KAIT observations
  55. LIGO/Virgo S200219ac: no counterpart candidates in the Swift/BAT observations
  56. GRB 200216B: Mondy and AbAO optical upper limits
  57. LIGO/Virgo S200213t: No EM counterparts found from continued GECKO observation of host galaxy candidates
  58. LIGO/Virgo S200213t : No significant candidates in FRAM - OAJ - TAROT - GRANDMA observations
  59. LIGO/Virgo S200213t: No notable candidates in GOTO imaging
  60. LIGO/Virgo S200213t: One additional candidate from the Zwicky Transient Facility
  61. LIGO/Virgo S200213t: More Candidates from the Zwicky Transient Facility
  62. LIGO/Virgo S200213t: No counterpart candidates in KAIT observations
  63. LIGO/Virgo S200208q : No significant candidates in TAROT - FRAM - GRANDMA observations
  64. LIGO/Virgo S200208q: no counterpart candidate in SVOM/C-GFT observations
  65. LIGO/Virgo S200213t: Candidates from the Zwicky Transient Facility
  66. LIGO/Virgo trigger S200213t: Possible host galaxies
  67. GRB 200131A: Tautenburg observations
  68. LIGO/Virgo S200208q: No counterpart candidates in KAIT observations
  69. LIGO/Virgo S200208q: No counterpart candidates in Fermi-LAT observations
  70. LIGO/Virgo S200208q: no counterpart candidates in the Swift/BAT observations
  71. Fermi trigger No 602817262: Global MASTER-Net observations report
  72. GRB 200205B: Swift-BAT refined analysis
  73. Fermi trigger No 602731380: Global MASTER-Net observations report
  74. Fermi trigger No 602626648: Global MASTER-Net observations report
  75. GRB 200205C: Fermi GBM Final Real-time Localization
  76. ZTF20aajnksq: Occulted by Earth at the time of GRB 200128A
  77. ZTF Discovery of ZTF20aajnksq: a Rapidly Fading Luminous Transient in the GRB 200128A Localiziation Region
  78. LIGO/Virgo S200128d: no counterpart candidate in SVOM/GWAC observations
  79. LIGO/Virgo S200128d : No significant candidates in FRAM - TAROT - GRANDMA observations
  80. Fermi trigger No 602071201: Global MASTER-Net observations report
  81. Fermi trigger No 602056641: Global MASTER-Net observations report
  82. LIGO/Virgo S200129m: no counterpart candidates in the Swift/BAT observations
  83. LIGO/Virgo S200128d: No counterpart candidates in KAIT observations
  84. LIGO/Virgo S200128d: no counterpart candidates in the Swift/BAT observations
  85. GRB 200125B: DDOTI/OAN optical observations report
  86. Fermi trigger No 601841483: Global MASTER-Net observations report
  87. Fermi trigger No 601729856: Global MASTER-Net observations report
  88. Fermi trigger No 601677816: Global MASTER-Net observations report
  89. LIGO/Virgo S200114f : No significant candidates in TAROT - FRAM - GRANDMA observations
  90. GRB 200122A: MITSuME Akeno optical upper limits
  91. Fermi trigger No 601363105: Global MASTER-Net observations report
  92. Konus-Wind observation of GRB 200120A
  93. Fermi trigger No 601254300: Global MASTER-Net observations report
  94. IceCube Alert 200120.78: Global MASTER-Net observations report
  95. LIGO/Virgo S200115j : No significant candidates in TAROT - FRAM - GRANDMA observations
  96. IceCube-200117A: One Additional Candidate Counterpart from the Zwicky Transient Facility
  97. IceCube-200117A: Candidate Counterpart from the Zwicky Transient Facility
  98. LIGO/Virgo S200105ae: More candidates from the Zwicky Transient Facility
  99. LIGO/Virgo S200114f: More candidates from the Zwicky Transient Facility
  100. LIGO/Virgo S200112r : No significant candidates in TAROT - FRAM - GRANDMA observations.

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