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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

45729 results found.

  1. GRB 241111A: Fermi GBM Final Real-time Localization
  2. GRB 241030B: TESS detection of optical counterpart
  3. LIGO/Virgo/KAGRA S241110br: Updated Sky localization
  4. LIGO/Virgo/KAGRA S241110bk: 1 counterpart neutrino candidate event from an IceCube neutrino search
  5. LIGO/Virgo/KAGRA S241110br: Identification of a GW compact binary merger candidate
  6. LIGO/Virgo/KAGRA S241109bn: Upper limits from EP-WXT observations
  7. Fermi trigger No 752878030: Global MASTER-Net observations report
  8. Integral GRB241109.89: Global MASTER-Net observations report
  9. LIGO/Virgo/KAGRA S241109bn: Coverage and upper limits from MAXI/GSC observations
  10. EP241109a: KAIT photometry and 3 m Shane spectroscopy from Lick observatory
  11. LIGO/Virgo/KAGRA S241109bn: Updated Sky localization and EM Bright Classification
  12. INTEGRAL detection of a burst from 1E 1841-045
  13. EP241107a: AbAO optical upper limit
  14. LIGO/Virgo/KAGRA S241109bn: Upper limits from Fermi-GBM Observations
  15. GRB 241108A: Further COLIBRÍ Upper Limits on the Optical Counterpart
  16. LIGO/Virgo/KAGRA S241109p: Updated Sky localization and Source Classification
  17. LIGO/Virgo/KAGRA S241109bn: Global MASTER-Net observations report
  18. LIGO/Virgo/KAGRA S241109bn: Identification of a GW compact binary merger candidate
  19. EP241109a: confirmation of a stellar flare by BOOTES-7
  20. EP241109a: EP on-board trigger and autonomous follow-up observation
  21. GRB 241108A: Swift-XRT observations
  22. LIGO/Virgo/KAGRA S241109p: Identification of a GW compact binary merger candidate
  23. EP241107A: MASTER optical observations of xray transient
  24. EP241107a: KAIT optical observations
  25. GRB 241108A: Swift ToO observations
  26. GRB 241030A: TESS observations
  27. GRB 241108A: COLIBRÍ Upper Limits on the Optical Counterpart
  28. GRB 241108A : a likely weak long GRB detected by SVOM/ECLAIRs
  29. EP241107a: Kinder optical follow-up observations
  30. GRB 241025A: radio detection with the VLA
  31. GRB 241104A: CALET Gamma-Ray Burst Monitor detection
  32. EP241107a: AKO Optical Afterglow Follow-Up Observations
  33. EP241107a: GSP detects optical counterpart
  34. EP241107a: Gemini-South spectroscopic confirmation (z = 0.456)
  35. GRB 241107A: SVOM/GRM detection of a short burst
  36. GRB 241105A: EP-FXT follow-up observations
  37. GRB 241105A: SVOM/GRM observation
  38. EP241107a: OHP/T193 photometric and spectroscopic observations
  39. GRB 241105a: PRIME near-infrared upper limits
  40. EP241107a: FTW Optical and NIR observations of the optical counterpart
  41. GRB 241105A: ePESSTO+ NTT optical afterglow detection
  42. EP241107a: GIT optical observations
  43. EP241107a: Global MASTER-Net observations report
  44. EP241107a: SVOM/C-GFT optical observations
  45. EP241107a: AKO Optical Afterglow Detection
  46. GRB 241025A: LBT optical observations
  47. GRB241105A: Gemini-South Optical Afterglow Detection
  48. EP241107a: EP on-board trigger and autonomous follow-up observation
  49. GRB 241105A: VLT/FORS2 optical afterglow rapid fading
  50. GRB 241105A: Swift/UVOT Detection
  51. EP241101a: CrAO ZTSH optical observations
  52. GRB 241105A: Swift/BAT-GUANO refined analysis of short burst with extended emission
  53. GRB 241030A: optical afterglow detection from the INAF Asiago Observatory
  54. GRB 241105A: BOOTES-7 optical detection
  55. GRB 241030A: Mondy optical observations
  56. GRB 241105A: Fermi GBM Observation of a Short Burst with Extended Emission
  57. Konus-Wind detection of GRB 241105A (short with extended emission)
  58. LIGO/Virgo/KAGRA S241106ba: 1 counterpart neutrino candidate event from an IceCube neutrino search
  59. LIGO/Virgo/KAGRA S241102o: 1 counterpart neutrino candidate event from an IceCube neutrino search
  60. Konus-Wind detection of GRB 241021A
  61. GRB 241105A: SVOM/VT optical afterglow observations
  62. GRB 241105A: Swift-XRT afterglow detection
  63. GRB 241105A: VLT/FORS2 spectroscopic redshift z = 2.681
  64. GRB 241104A: Swift-XRT observations
  65. GRB 240511A: LCO upper limits
  66. GRB 241104A: Fermi GBM Observation
  67. GRB 241104A: The SVOM/VT candidate in GCN circular 38086 is not an astrophysical source
  68. GRB 241105A: Swift ToO observations
  69. GRB 241105A: Swift/BAT-GUANO arcminute localization of a short burst
  70. GRB 241104A: Swift ToO observations
  71. GRB 241104A: NOT optical non-detection
  72. GRB 241105A: GOTO tentative optical counterpart candidate
  73. Fermi GRB 241105A: Global MASTER-Net observations report
  74. GRB 241104A: SVOM/VT optical candidate
  75. GRB 241105A: Fermi GBM Final Real-time Localization
  76. GRB 241104A/EP241104a: Optical upper limits with Kinder observations
  77. GRB 241104A: COLIBRÍ Upper Limits on the Optical Counterpart
  78. GRB 241104A: SVOM/GRM observation
  79. EP241104a: EP detection of GRB 241104A X-ray emission
  80. GRB 241010A: host galaxy redshift z = 0.977
  81. EP241101a NUTTelA-TAO / BSTI Measurements 2024-11-02
  82. GRB 241104A : Detection and localization by SVOM/ECLAIRs
  83. GRB 240821A: further radio observations with the VLA
  84. Fermi GRB 241104A: Global MASTER-Net observations report
  85. GRB 241104A: Fermi GBM Final Real-time Localization
  86. GRB 241030A: GRBAlpha detection
  87. EP241101a: EP-FXT observations update
  88. EP241103a: GIT optical upper limit
  89. EP241021a: OHP/T193 further optical observations
  90. LIGO/Virgo/KAGRA S241104a: Retraction of GW compact binary merger candidate
  91. Fermi trigger No 752365806: Global MASTER-Net observations report
  92. LIGO/Virgo/KAGRA S241102br: OHP/T193 optical observations
  93. LIGO/Virgo/KAGRA S241102cy: Updated Sky localization
  94. EP241103a: GOTO optical upper limit
  95. LIGO/Virgo/KAGRA S241102br: Updated Sky localization
  96. EP241101a: Possible detection of an optical counterpart with FTW
  97. EP241103a: Swift XRT detection and improved X-ray position
  98. EP241021a: continued SOAR observations
  99. EP241101a: Optical upper limits with Kinder observations
  100. EP241101a: OHP/T193 optical observations

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